chore(db): use one SQLite database per folder (#10042)

This changes the database structure to use one database per folder, with
a small main database to coordinate. Reverts the prior change to buffer
all files in memory when pulling, meaning there is now a phase where the
WAL file will grow significantly, at least for initial sync of folders
with many directories.

---------

Co-authored-by: bt90 <[email protected]>

internal/db/interface.go

@@ -36,13 +36,13 @@ type DB interface {
 	// required.
 	AllGlobalFiles(folder string) (iter.Seq[FileMetadata], func() error)
 	AllGlobalFilesPrefix(folder string, prefix string) (iter.Seq[FileMetadata], func() error)
-	AllLocalBlocksWithHash(hash []byte) (iter.Seq[BlockMapEntry], func() error)
 	AllLocalFiles(folder string, device protocol.DeviceID) (iter.Seq[protocol.FileInfo], func() error)
 	AllLocalFilesBySequence(folder string, device protocol.DeviceID, startSeq int64, limit int) (iter.Seq[protocol.FileInfo], func() error)
 	AllLocalFilesWithPrefix(folder string, device protocol.DeviceID, prefix string) (iter.Seq[protocol.FileInfo], func() error)
 	AllLocalFilesWithBlocksHash(folder string, h []byte) (iter.Seq[FileMetadata], func() error)
-	AllLocalFilesWithBlocksHashAnyFolder(h []byte) (iter.Seq2[string, FileMetadata], func() error)
 	AllNeededGlobalFiles(folder string, device protocol.DeviceID, order config.PullOrder, limit, offset int) (iter.Seq[protocol.FileInfo], func() error)
+	AllLocalBlocksWithHash(hash []byte) ([]BlockMapEntry, error)
+	AllLocalFilesWithBlocksHashAnyFolder(hash []byte) (map[string][]FileMetadata, error)
 
 	// Cleanup
 	DropAllFiles(folder string, device protocol.DeviceID) error

internal/db/metrics.go

@@ -67,9 +67,9 @@ func (m metricsDB) AllLocalFilesWithBlocksHash(folder string, h []byte) (iter.Se
 	return m.DB.AllLocalFilesWithBlocksHash(folder, h)
 }
 
-func (m metricsDB) AllLocalFilesWithBlocksHashAnyFolder(h []byte) (iter.Seq2[string, FileMetadata], func() error) {
+func (m metricsDB) AllLocalFilesWithBlocksHashAnyFolder(hash []byte) (map[string][]FileMetadata, error) {
 	defer m.account("-", "AllLocalFilesWithBlocksHashAnyFolder")()
-	return m.DB.AllLocalFilesWithBlocksHashAnyFolder(h)
+	return m.DB.AllLocalFilesWithBlocksHashAnyFolder(hash)
 }
 
 func (m metricsDB) AllGlobalFiles(folder string) (iter.Seq[FileMetadata], func() error) {
@@ -107,7 +107,7 @@ func (m metricsDB) GetGlobalAvailability(folder, file string) ([]protocol.Device
 	return m.DB.GetGlobalAvailability(folder, file)
 }
 
-func (m metricsDB) AllLocalBlocksWithHash(hash []byte) (iter.Seq[BlockMapEntry], func() error) {
+func (m metricsDB) AllLocalBlocksWithHash(hash []byte) ([]BlockMapEntry, error) {
 	defer m.account("-", "AllLocalBlocksWithHash")()
 	return m.DB.AllLocalBlocksWithHash(hash)
 }

internal/db/sqlite/basedb.go

@@ -0,0 +1,251 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"database/sql"
+	"embed"
+	"io/fs"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"text/template"
+	"time"
+
+	"github.com/jmoiron/sqlx"
+	"github.com/syncthing/syncthing/lib/build"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+const currentSchemaVersion = 1
+
+//go:embed sql/**
+var embedded embed.FS
+
+type baseDB struct {
+	path     string
+	baseName string
+	sql      *sqlx.DB
+
+	updateLock       sync.Mutex
+	updatePoints     int
+	checkpointsCount int
+
+	statementsMut sync.RWMutex
+	statements    map[string]*sqlx.Stmt
+	tplInput      map[string]any
+}
+
+func openBase(path string, maxConns int, pragmas, schemaScripts, migrationScripts []string) (*baseDB, error) {
+	// Open the database with options to enable foreign keys and recursive
+	// triggers (needed for the delete+insert triggers on row replace).
+	sqlDB, err := sqlx.Open(dbDriver, "file:"+path+"?"+commonOptions)
+	if err != nil {
+		return nil, wrap(err)
+	}
+
+	sqlDB.SetMaxOpenConns(maxConns)
+
+	for _, pragma := range pragmas {
+		if _, err := sqlDB.Exec("PRAGMA " + pragma); err != nil {
+			return nil, wrap(err, "PRAGMA "+pragma)
+		}
+	}
+
+	db := &baseDB{
+		path:       path,
+		baseName:   filepath.Base(path),
+		sql:        sqlDB,
+		statements: make(map[string]*sqlx.Stmt),
+	}
+
+	for _, script := range schemaScripts {
+		if err := db.runScripts(script); err != nil {
+			return nil, wrap(err)
+		}
+	}
+
+	ver, _ := db.getAppliedSchemaVersion()
+	if ver.SchemaVersion > 0 {
+		filter := func(scr string) bool {
+			scr = filepath.Base(scr)
+			nstr, _, ok := strings.Cut(scr, "-")
+			if !ok {
+				return false
+			}
+			n, err := strconv.ParseInt(nstr, 10, 32)
+			if err != nil {
+				return false
+			}
+			return int(n) > ver.SchemaVersion
+		}
+		for _, script := range migrationScripts {
+			if err := db.runScripts(script, filter); err != nil {
+				return nil, wrap(err)
+			}
+		}
+	}
+
+	// Set the current schema version, if not already set
+	if err := db.setAppliedSchemaVersion(currentSchemaVersion); err != nil {
+		return nil, wrap(err)
+	}
+
+	db.tplInput = map[string]any{
+		"FlagLocalUnsupported": protocol.FlagLocalUnsupported,
+		"FlagLocalIgnored":     protocol.FlagLocalIgnored,
+		"FlagLocalMustRescan":  protocol.FlagLocalMustRescan,
+		"FlagLocalReceiveOnly": protocol.FlagLocalReceiveOnly,
+		"FlagLocalGlobal":      protocol.FlagLocalGlobal,
+		"FlagLocalNeeded":      protocol.FlagLocalNeeded,
+		"SyncthingVersion":     build.LongVersion,
+	}
+
+	return db, nil
+}
+
+func (s *baseDB) Close() error {
+	s.updateLock.Lock()
+	s.statementsMut.Lock()
+	defer s.updateLock.Unlock()
+	defer s.statementsMut.Unlock()
+	for _, stmt := range s.statements {
+		stmt.Close()
+	}
+	return wrap(s.sql.Close())
+}
+
+var tplFuncs = template.FuncMap{
+	"or": func(vs ...int) int {
+		v := vs[0]
+		for _, ov := range vs[1:] {
+			v |= ov
+		}
+		return v
+	},
+}
+
+// stmt returns a prepared statement for the given SQL string, after
+// applying local template expansions. The statement is cached.
+func (s *baseDB) stmt(tpl string) stmt {
+	tpl = strings.TrimSpace(tpl)
+
+	// Fast concurrent lookup of cached statement
+	s.statementsMut.RLock()
+	stmt, ok := s.statements[tpl]
+	s.statementsMut.RUnlock()
+	if ok {
+		return stmt
+	}
+
+	// On miss, take the full lock, check again
+	s.statementsMut.Lock()
+	defer s.statementsMut.Unlock()
+	stmt, ok = s.statements[tpl]
+	if ok {
+		return stmt
+	}
+
+	// Apply template expansions
+	var sb strings.Builder
+	compTpl := template.Must(template.New("tpl").Funcs(tplFuncs).Parse(tpl))
+	if err := compTpl.Execute(&sb, s.tplInput); err != nil {
+		panic("bug: bad template: " + err.Error())
+	}
+
+	// Prepare and cache
+	stmt, err := s.sql.Preparex(sb.String())
+	if err != nil {
+		return failedStmt{err}
+	}
+	s.statements[tpl] = stmt
+	return stmt
+}
+
+type stmt interface {
+	Exec(args ...any) (sql.Result, error)
+	Get(dest any, args ...any) error
+	Queryx(args ...any) (*sqlx.Rows, error)
+	Select(dest any, args ...any) error
+}
+
+type failedStmt struct {
+	err error
+}
+
+func (f failedStmt) Exec(_ ...any) (sql.Result, error)   { return nil, f.err }
+func (f failedStmt) Get(_ any, _ ...any) error           { return f.err }
+func (f failedStmt) Queryx(_ ...any) (*sqlx.Rows, error) { return nil, f.err }
+func (f failedStmt) Select(_ any, _ ...any) error        { return f.err }
+
+func (s *baseDB) runScripts(glob string, filter ...func(s string) bool) error {
+	scripts, err := fs.Glob(embedded, glob)
+	if err != nil {
+		return wrap(err)
+	}
+
+	tx, err := s.sql.Begin()
+	if err != nil {
+		return wrap(err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+
+nextScript:
+	for _, scr := range scripts {
+		for _, fn := range filter {
+			if !fn(scr) {
+				l.Debugln(s.baseName, "skipping script", scr)
+				continue nextScript
+			}
+		}
+		l.Debugln(s.baseName, "executing script", scr)
+		bs, err := fs.ReadFile(embedded, scr)
+		if err != nil {
+			return wrap(err, scr)
+		}
+		// SQLite requires one statement per exec, so we split the init
+		// files on lines containing only a semicolon and execute them
+		// separately. We require it on a separate line because there are
+		// also statement-internal semicolons in the triggers.
+		for _, stmt := range strings.Split(string(bs), "\n;") {
+			if _, err := tx.Exec(stmt); err != nil {
+				return wrap(err, stmt)
+			}
+		}
+	}
+
+	return wrap(tx.Commit())
+}
+
+type schemaVersion struct {
+	SchemaVersion    int
+	AppliedAt        int64
+	SyncthingVersion string
+}
+
+func (s *schemaVersion) AppliedTime() time.Time {
+	return time.Unix(0, s.AppliedAt)
+}
+
+func (s *baseDB) setAppliedSchemaVersion(ver int) error {
+	_, err := s.stmt(`
+		INSERT OR IGNORE INTO schemamigrations (schema_version, applied_at, syncthing_version)
+		VALUES (?, ?, ?)
+	`).Exec(ver, time.Now().UnixNano(), build.LongVersion)
+	return wrap(err)
+}
+
+func (s *baseDB) getAppliedSchemaVersion() (schemaVersion, error) {
+	var v schemaVersion
+	err := s.stmt(`
+		SELECT schema_version as schemaversion, applied_at as appliedat, syncthing_version as syncthingversion FROM schemamigrations
+		ORDER BY schema_version DESC
+		LIMIT 1
+	`).Get(&v)
+	return v, wrap(err)
+}

internal/db/sqlite/db.go

@@ -1,88 +0,0 @@
-// Copyright (C) 2025 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at https://mozilla.org/MPL/2.0/.
-
-package sqlite
-
-import (
-	"sync"
-	"time"
-
-	"github.com/jmoiron/sqlx"
-	"github.com/syncthing/syncthing/internal/db"
-	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/thejerf/suture/v4"
-)
-
-type DB struct {
-	sql             *sqlx.DB
-	localDeviceIdx  int64
-	deleteRetention time.Duration
-
-	updateLock   sync.Mutex
-	updatePoints int
-
-	statementsMut sync.RWMutex
-	statements    map[string]*sqlx.Stmt
-	tplInput      map[string]any
-}
-
-var _ db.DB = (*DB)(nil)
-
-type Option func(*DB)
-
-func WithDeleteRetention(d time.Duration) Option {
-	return func(s *DB) {
-		s.deleteRetention = d
-	}
-}
-
-func (s *DB) Close() error {
-	s.updateLock.Lock()
-	s.statementsMut.Lock()
-	defer s.updateLock.Unlock()
-	defer s.statementsMut.Unlock()
-	for _, stmt := range s.statements {
-		stmt.Close()
-	}
-	return wrap(s.sql.Close())
-}
-
-func (s *DB) Service(maintenanceInterval time.Duration) suture.Service {
-	return newService(s, maintenanceInterval)
-}
-
-func (s *DB) ListFolders() ([]string, error) {
-	var res []string
-	err := s.stmt(`
-		SELECT folder_id FROM folders
-		ORDER BY folder_id
-	`).Select(&res)
-	return res, wrap(err)
-}
-
-func (s *DB) ListDevicesForFolder(folder string) ([]protocol.DeviceID, error) {
-	var res []string
-	err := s.stmt(`
-		SELECT d.device_id FROM counts s
-		INNER JOIN folders o ON o.idx = s.folder_idx
-		INNER JOIN devices d ON d.idx = s.device_idx
-		WHERE o.folder_id = ? AND s.count > 0 AND s.device_idx != {{.LocalDeviceIdx}}
-		GROUP BY d.device_id
-		ORDER BY d.device_id
-	`).Select(&res, folder)
-	if err != nil {
-		return nil, wrap(err)
-	}
-
-	devs := make([]protocol.DeviceID, len(res))
-	for i, s := range res {
-		devs[i], err = protocol.DeviceIDFromString(s)
-		if err != nil {
-			return nil, wrap(err)
-		}
-	}
-	return devs, nil
-}

internal/db/sqlite/db_folderdb.go

@@ -0,0 +1,391 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"iter"
+	"path/filepath"
+	"time"
+
+	"github.com/syncthing/syncthing/internal/db"
+	"github.com/syncthing/syncthing/internal/itererr"
+	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+var errNoSuchFolder = errors.New("no such folder")
+
+func (s *DB) getFolderDB(folder string, create bool) (*folderDB, error) {
+	// Check for an already open database
+	s.folderDBsMut.RLock()
+	fdb, ok := s.folderDBs[folder]
+	s.folderDBsMut.RUnlock()
+	if ok {
+		return fdb, nil
+	}
+
+	// Check for an existing folder. If we're not supposed to create the
+	// folder, we don't move on if it doesn't already have an ID.
+	var idx int64
+	if err := s.stmt(`
+		SELECT idx FROM folders
+		WHERE folder_id = ?
+	`).Get(&idx, folder); err != nil && !errors.Is(err, sql.ErrNoRows) {
+		return nil, wrap(err)
+	}
+	if idx == 0 && !create {
+		return nil, errNoSuchFolder
+	}
+
+	// Create a folder ID and database if it does not already exist
+	s.folderDBsMut.Lock()
+	defer s.folderDBsMut.Unlock()
+	if fdb, ok := s.folderDBs[folder]; ok {
+		return fdb, nil
+	}
+
+	var err error
+	if idx == 0 {
+		// First time we want to access this folder, need to create a new
+		// folder ID
+		idx, err = s.folderIdxLocked(folder)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	name := fmt.Sprintf("folder.%04x.db", idx)
+	path := filepath.Join(s.pathBase, name)
+	fdb, err = s.folderDBOpener(folder, path, s.deleteRetention)
+	if err != nil {
+		return nil, err
+	}
+	s.folderDBs[folder] = fdb
+	return fdb, nil
+}
+
+func (s *DB) Update(folder string, device protocol.DeviceID, fs []protocol.FileInfo) error {
+	fdb, err := s.getFolderDB(folder, true)
+	if err != nil {
+		return err
+	}
+	return fdb.Update(device, fs)
+}
+
+func (s *DB) GetDeviceFile(folder string, device protocol.DeviceID, file string) (protocol.FileInfo, bool, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return protocol.FileInfo{}, false, nil
+	}
+	if err != nil {
+		return protocol.FileInfo{}, false, err
+	}
+	return fdb.GetDeviceFile(device, file)
+}
+
+func (s *DB) GetGlobalAvailability(folder, file string) ([]protocol.DeviceID, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return fdb.GetGlobalAvailability(file)
+}
+
+func (s *DB) GetGlobalFile(folder string, file string) (protocol.FileInfo, bool, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return protocol.FileInfo{}, false, nil
+	}
+	if err != nil {
+		return protocol.FileInfo{}, false, err
+	}
+	return fdb.GetGlobalFile(file)
+}
+
+func (s *DB) AllGlobalFiles(folder string) (iter.Seq[db.FileMetadata], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return err }
+	}
+	return fdb.AllGlobalFiles()
+}
+
+func (s *DB) AllGlobalFilesPrefix(folder string, prefix string) (iter.Seq[db.FileMetadata], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return err }
+	}
+	return fdb.AllGlobalFilesPrefix(prefix)
+}
+
+func (s *DB) AllLocalBlocksWithHash(hash []byte) ([]db.BlockMapEntry, error) {
+	var entries []db.BlockMapEntry
+	err := s.forEachFolder(func(fdb *folderDB) error {
+		es, err := itererr.Collect(fdb.AllLocalBlocksWithHash(hash))
+		entries = append(entries, es...)
+		return err
+	})
+	return entries, err
+}
+
+func (s *DB) AllLocalFilesWithBlocksHashAnyFolder(hash []byte) (map[string][]db.FileMetadata, error) {
+	res := make(map[string][]db.FileMetadata)
+	err := s.forEachFolder(func(fdb *folderDB) error {
+		files, err := itererr.Collect(fdb.AllLocalFilesWithBlocksHash(hash))
+		res[fdb.folderID] = files
+		return err
+	})
+	return res, err
+}
+
+func (s *DB) AllLocalFiles(folder string, device protocol.DeviceID) (iter.Seq[protocol.FileInfo], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return err }
+	}
+	return fdb.AllLocalFiles(device)
+}
+
+func (s *DB) AllLocalFilesBySequence(folder string, device protocol.DeviceID, startSeq int64, limit int) (iter.Seq[protocol.FileInfo], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return err }
+	}
+	return fdb.AllLocalFilesBySequence(device, startSeq, limit)
+}
+
+func (s *DB) AllLocalFilesWithPrefix(folder string, device protocol.DeviceID, prefix string) (iter.Seq[protocol.FileInfo], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return err }
+	}
+	return fdb.AllLocalFilesWithPrefix(device, prefix)
+}
+
+func (s *DB) AllLocalFilesWithBlocksHash(folder string, h []byte) (iter.Seq[db.FileMetadata], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(db.FileMetadata) bool) {}, func() error { return err }
+	}
+	return fdb.AllLocalFilesWithBlocksHash(h)
+}
+
+func (s *DB) AllNeededGlobalFiles(folder string, device protocol.DeviceID, order config.PullOrder, limit, offset int) (iter.Seq[protocol.FileInfo], func() error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return nil }
+	}
+	if err != nil {
+		return func(yield func(protocol.FileInfo) bool) {}, func() error { return err }
+	}
+	return fdb.AllNeededGlobalFiles(device, order, limit, offset)
+}
+
+func (s *DB) DropAllFiles(folder string, device protocol.DeviceID) error {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	return fdb.DropAllFiles(device)
+}
+
+func (s *DB) DropFilesNamed(folder string, device protocol.DeviceID, names []string) error {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	return fdb.DropFilesNamed(device, names)
+}
+
+func (s *DB) ListDevicesForFolder(folder string) ([]protocol.DeviceID, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return fdb.ListDevicesForFolder()
+}
+
+func (s *DB) RemoteSequences(folder string) (map[protocol.DeviceID]int64, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return fdb.RemoteSequences()
+}
+
+func (s *DB) CountGlobal(folder string) (db.Counts, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return db.Counts{}, nil
+	}
+	if err != nil {
+		return db.Counts{}, err
+	}
+	return fdb.CountGlobal()
+}
+
+func (s *DB) CountLocal(folder string, device protocol.DeviceID) (db.Counts, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return db.Counts{}, nil
+	}
+	if err != nil {
+		return db.Counts{}, err
+	}
+	return fdb.CountLocal(device)
+}
+
+func (s *DB) CountNeed(folder string, device protocol.DeviceID) (db.Counts, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return db.Counts{}, nil
+	}
+	if err != nil {
+		return db.Counts{}, err
+	}
+	return fdb.CountNeed(device)
+}
+
+func (s *DB) CountReceiveOnlyChanged(folder string) (db.Counts, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return db.Counts{}, nil
+	}
+	if err != nil {
+		return db.Counts{}, err
+	}
+	return fdb.CountReceiveOnlyChanged()
+}
+
+func (s *DB) DropAllIndexIDs() error {
+	return s.forEachFolder(func(fdb *folderDB) error {
+		return fdb.DropAllIndexIDs()
+	})
+}
+
+func (s *DB) GetIndexID(folder string, device protocol.DeviceID) (protocol.IndexID, error) {
+	fdb, err := s.getFolderDB(folder, true)
+	if err != nil {
+		return 0, err
+	}
+	return fdb.GetIndexID(device)
+}
+
+func (s *DB) SetIndexID(folder string, device protocol.DeviceID, id protocol.IndexID) error {
+	fdb, err := s.getFolderDB(folder, true)
+	if err != nil {
+		return err
+	}
+	return fdb.SetIndexID(device, id)
+}
+
+func (s *DB) GetDeviceSequence(folder string, device protocol.DeviceID) (int64, error) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return 0, nil
+	}
+	if err != nil {
+		return 0, err
+	}
+	return fdb.GetDeviceSequence(device)
+}
+
+func (s *DB) DeleteMtime(folder, name string) error {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	return fdb.DeleteMtime(name)
+}
+
+func (s *DB) GetMtime(folder, name string) (ondisk, virtual time.Time) {
+	fdb, err := s.getFolderDB(folder, false)
+	if errors.Is(err, errNoSuchFolder) {
+		return time.Time{}, time.Time{}
+	}
+	if err != nil {
+		return time.Time{}, time.Time{}
+	}
+	return fdb.GetMtime(name)
+}
+
+func (s *DB) PutMtime(folder, name string, ondisk, virtual time.Time) error {
+	fdb, err := s.getFolderDB(folder, true)
+	if err != nil {
+		return err
+	}
+	return fdb.PutMtime(name, ondisk, virtual)
+}
+
+func (s *DB) DropDevice(device protocol.DeviceID) error {
+	return s.forEachFolder(func(fdb *folderDB) error {
+		return fdb.DropDevice(device)
+	})
+}
+
+// forEachFolder runs the function for each currently open folderDB,
+// returning the first error that was encountered.
+func (s *DB) forEachFolder(fn func(fdb *folderDB) error) error {
+	folders, err := s.ListFolders()
+	if err != nil {
+		return err
+	}
+
+	var firstError error
+	for _, folder := range folders {
+		fdb, err := s.getFolderDB(folder, false)
+		if err != nil {
+			if firstError == nil {
+				firstError = err
+			}
+			continue
+		}
+		if err := fn(fdb); err != nil && firstError == nil {
+			firstError = err
+		}
+	}
+	return firstError
+}

internal/db/sqlite/db_kv.go

@@ -13,7 +13,7 @@ import (
 	"github.com/syncthing/syncthing/internal/db"
 )
 
-func (s *DB) GetKV(key string) ([]byte, error) {
+func (s *baseDB) GetKV(key string) ([]byte, error) {
 	var val []byte
 	if err := s.stmt(`
 		SELECT value FROM kv
@@ -24,7 +24,7 @@ func (s *DB) GetKV(key string) ([]byte, error) {
 	return val, nil
 }
 
-func (s *DB) PutKV(key string, val []byte) error {
+func (s *baseDB) PutKV(key string, val []byte) error {
 	s.updateLock.Lock()
 	defer s.updateLock.Unlock()
 	_, err := s.stmt(`
@@ -34,7 +34,7 @@ func (s *DB) PutKV(key string, val []byte) error {
 	return wrap(err)
 }
 
-func (s *DB) DeleteKV(key string) error {
+func (s *baseDB) DeleteKV(key string) error {
 	s.updateLock.Lock()
 	defer s.updateLock.Unlock()
 	_, err := s.stmt(`
@@ -43,7 +43,7 @@ func (s *DB) DeleteKV(key string) error {
 	return wrap(err)
 }
 
-func (s *DB) PrefixKV(prefix string) (iter.Seq[db.KeyValue], func() error) {
+func (s *baseDB) PrefixKV(prefix string) (iter.Seq[db.KeyValue], func() error) {
 	var rows *sqlx.Rows
 	var err error
 	if prefix == "" {

internal/db/sqlite/db_local_test.go

@@ -9,8 +9,6 @@ package sqlite
 import (
 	"testing"
 
-	"github.com/syncthing/syncthing/internal/db"
-	"github.com/syncthing/syncthing/internal/itererr"
 	"github.com/syncthing/syncthing/lib/protocol"
 )
 
@@ -52,7 +50,7 @@ func TestBlocks(t *testing.T) {
 
 	// Search for blocks
 
-	vals, err := itererr.Collect(db.AllLocalBlocksWithHash([]byte{1, 2, 3}))
+	vals, err := db.AllLocalBlocksWithHash([]byte{1, 2, 3})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -66,27 +64,23 @@ func TestBlocks(t *testing.T) {
 
 	// Get FileInfos for those blocks
 
-	found := 0
-	it, errFn := db.AllLocalFilesWithBlocksHashAnyFolder(vals[0].BlocklistHash)
-	for folder, fileInfo := range it {
-		if folder != folderID {
-			t.Fatal("should be same folder")
-		}
-		if fileInfo.Name != "file1" {
-			t.Fatal("should be file1")
-		}
-		found++
-	}
-	if err := errFn(); err != nil {
+	res, err := db.AllLocalFilesWithBlocksHashAnyFolder(vals[0].BlocklistHash)
+	if err != nil {
 		t.Fatal(err)
 	}
-	if found != 1 {
+	if len(res) != 1 {
+		t.Fatal("should return one folder")
+	}
+	if len(res[folderID]) != 1 {
 		t.Fatal("should find one file")
 	}
+	if res[folderID][0].Name != "file1" {
+		t.Fatal("should be file1")
+	}
 
 	// Get the other blocks
 
-	vals, err = itererr.Collect(db.AllLocalBlocksWithHash([]byte{3, 4, 5}))
+	vals, err = db.AllLocalBlocksWithHash([]byte{3, 4, 5})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -125,7 +119,10 @@ func TestBlocksDeleted(t *testing.T) {
 
 	// We should find one entry for the block hash
 	search := file.Blocks[0].Hash
-	es := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(search))
+	es, err := sdb.AllLocalBlocksWithHash(search)
+	if err != nil {
+		t.Fatal(err)
+	}
 	if len(es) != 1 {
 		t.Fatal("expected one hit")
 	}
@@ -137,13 +134,17 @@ func TestBlocksDeleted(t *testing.T) {
 	}
 
 	// Searching for the old hash should yield no hits
-	if hits := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(search)); len(hits) != 0 {
+	if hits, err := sdb.AllLocalBlocksWithHash(search); err != nil {
+		t.Fatal(err)
+	} else if len(hits) != 0 {
 		t.Log(hits)
 		t.Error("expected no hits")
 	}
 
 	// Searching for the new hash should yield one hits
-	if hits := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(file.Blocks[0].Hash)); len(hits) != 1 {
+	if hits, err := sdb.AllLocalBlocksWithHash(file.Blocks[0].Hash); err != nil {
+		t.Fatal(err)
+	} else if len(hits) != 1 {
 		t.Log(hits)
 		t.Error("expected one hit")
 	}

internal/db/sqlite/db_mtimes.go

@@ -1,54 +0,0 @@
-// Copyright (C) 2025 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at https://mozilla.org/MPL/2.0/.
-
-package sqlite
-
-import (
-	"time"
-)
-
-func (s *DB) GetMtime(folder, name string) (ondisk, virtual time.Time) {
-	var res struct {
-		Ondisk  int64
-		Virtual int64
-	}
-	if err := s.stmt(`
-		SELECT m.ondisk, m.virtual FROM mtimes m
-		INNER JOIN folders o ON o.idx = m.folder_idx
-		WHERE o.folder_id = ? AND m.name = ?
-	`).Get(&res, folder, name); err != nil {
-		return time.Time{}, time.Time{}
-	}
-	return time.Unix(0, res.Ondisk), time.Unix(0, res.Virtual)
-}
-
-func (s *DB) PutMtime(folder, name string, ondisk, virtual time.Time) error {
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err)
-	}
-	_, err = s.stmt(`
-		INSERT OR REPLACE INTO mtimes (folder_idx, name, ondisk, virtual)
-		VALUES (?, ?, ?, ?)
-	`).Exec(folderIdx, name, ondisk.UnixNano(), virtual.UnixNano())
-	return wrap(err)
-}
-
-func (s *DB) DeleteMtime(folder, name string) error {
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err)
-	}
-	_, err = s.stmt(`
-		DELETE FROM mtimes
-		WHERE folder_idx = ? AND name = ?
-	`).Exec(folderIdx, name)
-	return wrap(err)
-}

internal/db/sqlite/db_open.go

@@ -7,57 +7,104 @@
 package sqlite
 
 import (
-	"database/sql"
 	"os"
 	"path/filepath"
-	"strconv"
-	"strings"
-	"text/template"
+	"sync"
+	"time"
 
-	"github.com/jmoiron/sqlx"
-	"github.com/syncthing/syncthing/lib/build"
-	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/internal/db"
 )
 
-const maxDBConns = 128
+const maxDBConns = 16
+
+type DB struct {
+	pathBase        string
+	deleteRetention time.Duration
+
+	*baseDB
+
+	folderDBsMut   sync.RWMutex
+	folderDBs      map[string]*folderDB
+	folderDBOpener func(folder, path string, deleteRetention time.Duration) (*folderDB, error)
+}
+
+var _ db.DB = (*DB)(nil)
+
+type Option func(*DB)
+
+func WithDeleteRetention(d time.Duration) Option {
+	return func(s *DB) {
+		s.deleteRetention = d
+	}
+}
 
 func Open(path string, opts ...Option) (*DB, error) {
-	// Open the database with options to enable foreign keys and recursive
-	// triggers (needed for the delete+insert triggers on row replace).
-	sqlDB, err := sqlx.Open(dbDriver, "file:"+path+"?"+commonOptions)
-	if err != nil {
-		return nil, wrap(err)
+	pragmas := []string{
+		"journal_mode = WAL",
+		"optimize = 0x10002",
+		"auto_vacuum = INCREMENTAL",
+		"default_temp_store = MEMORY",
+		"temp_store = MEMORY",
+	}
+	schemas := []string{
+		"sql/schema/common/*",
+		"sql/schema/main/*",
 	}
-	sqlDB.SetMaxOpenConns(maxDBConns)
-	if _, err := sqlDB.Exec(`PRAGMA journal_mode = WAL`); err != nil {
-		return nil, wrap(err, "PRAGMA journal_mode")
+
+	os.MkdirAll(path, 0o700)
+	mainPath := filepath.Join(path, "main.db")
+	mainBase, err := openBase(mainPath, maxDBConns, pragmas, schemas, nil)
+	if err != nil {
+		return nil, err
 	}
-	if _, err := sqlDB.Exec(`PRAGMA optimize = 0x10002`); err != nil {
-		// https://www.sqlite.org/pragma.html#pragma_optimize
-		return nil, wrap(err, "PRAGMA optimize")
+
+	db := &DB{
+		pathBase:       path,
+		baseDB:         mainBase,
+		folderDBs:      make(map[string]*folderDB),
+		folderDBOpener: openFolderDB,
 	}
-	return openCommon(sqlDB, opts...)
+
+	return db, nil
 }
 
 // Open the database with options suitable for the migration inserts. This
 // is not a safe mode of operation for normal processing, use only for bulk
 // inserts with a close afterwards.
 func OpenForMigration(path string) (*DB, error) {
-	sqlDB, err := sqlx.Open(dbDriver, "file:"+path+"?"+commonOptions)
+	pragmas := []string{
+		"journal_mode = OFF",
+		"default_temp_store = MEMORY",
+		"temp_store = MEMORY",
+		"foreign_keys = 0",
+		"synchronous = 0",
+		"locking_mode = EXCLUSIVE",
+	}
+	schemas := []string{
+		"sql/schema/common/*",
+		"sql/schema/main/*",
+	}
+
+	os.MkdirAll(path, 0o700)
+	mainPath := filepath.Join(path, "main.db")
+	mainBase, err := openBase(mainPath, 1, pragmas, schemas, nil)
 	if err != nil {
-		return nil, wrap(err, "open")
-	}
-	sqlDB.SetMaxOpenConns(1)
-	if _, err := sqlDB.Exec(`PRAGMA foreign_keys = 0`); err != nil {
-		return nil, wrap(err, "PRAGMA foreign_keys")
-	}
-	if _, err := sqlDB.Exec(`PRAGMA journal_mode = OFF`); err != nil {
-		return nil, wrap(err, "PRAGMA journal_mode")
+		return nil, err
 	}
-	if _, err := sqlDB.Exec(`PRAGMA synchronous = 0`); err != nil {
-		return nil, wrap(err, "PRAGMA synchronous")
+
+	db := &DB{
+		pathBase:       path,
+		baseDB:         mainBase,
+		folderDBs:      make(map[string]*folderDB),
+		folderDBOpener: openFolderDBForMigration,
 	}
-	return openCommon(sqlDB)
+
+	// // Touch device IDs that should always exist and have a low index
+	// // numbers, and will never change
+	// db.localDeviceIdx, _ = db.deviceIdxLocked(protocol.LocalDeviceID)
+	// db.tplInput["LocalDeviceIdx"] = db.localDeviceIdx
+
+	return db, nil
 }
 
 func OpenTemp() (*DB, error) {
@@ -73,134 +120,12 @@ func OpenTemp() (*DB, error) {
 	return Open(path)
 }
 
-func openCommon(sqlDB *sqlx.DB, opts ...Option) (*DB, error) {
-	if _, err := sqlDB.Exec(`PRAGMA auto_vacuum = INCREMENTAL`); err != nil {
-		return nil, wrap(err, "PRAGMA auto_vacuum")
-	}
-	if _, err := sqlDB.Exec(`PRAGMA default_temp_store = MEMORY`); err != nil {
-		return nil, wrap(err, "PRAGMA default_temp_store")
-	}
-	if _, err := sqlDB.Exec(`PRAGMA temp_store = MEMORY`); err != nil {
-		return nil, wrap(err, "PRAGMA temp_store")
-	}
-
-	db := &DB{
-		sql:             sqlDB,
-		deleteRetention: defaultDeleteRetention,
-		statements:      make(map[string]*sqlx.Stmt),
-	}
-	for _, opt := range opts {
-		opt(db)
-	}
-	if db.deleteRetention > 0 && db.deleteRetention < minDeleteRetention {
-		db.deleteRetention = minDeleteRetention
-	}
-
-	if err := db.runScripts("sql/schema/*"); err != nil {
-		return nil, wrap(err)
-	}
-
-	ver, _ := db.getAppliedSchemaVersion()
-	if ver.SchemaVersion > 0 {
-		filter := func(scr string) bool {
-			scr = filepath.Base(scr)
-			nstr, _, ok := strings.Cut(scr, "-")
-			if !ok {
-				return false
-			}
-			n, err := strconv.ParseInt(nstr, 10, 32)
-			if err != nil {
-				return false
-			}
-			return int(n) > ver.SchemaVersion
-		}
-		if err := db.runScripts("sql/migrations/*", filter); err != nil {
-			return nil, wrap(err)
-		}
-	}
-
-	// Touch device IDs that should always exist and have a low index
-	// numbers, and will never change
-	db.localDeviceIdx, _ = db.deviceIdxLocked(protocol.LocalDeviceID)
-
-	// Set the current schema version, if not already set
-	if err := db.setAppliedSchemaVersion(currentSchemaVersion); err != nil {
-		return nil, wrap(err)
-	}
-
-	db.tplInput = map[string]any{
-		"FlagLocalUnsupported": protocol.FlagLocalUnsupported,
-		"FlagLocalIgnored":     protocol.FlagLocalIgnored,
-		"FlagLocalMustRescan":  protocol.FlagLocalMustRescan,
-		"FlagLocalReceiveOnly": protocol.FlagLocalReceiveOnly,
-		"FlagLocalGlobal":      protocol.FlagLocalGlobal,
-		"FlagLocalNeeded":      protocol.FlagLocalNeeded,
-		"LocalDeviceIdx":       db.localDeviceIdx,
-		"SyncthingVersion":     build.LongVersion,
-	}
-
-	return db, nil
-}
-
-var tplFuncs = template.FuncMap{
-	"or": func(vs ...int) int {
-		v := vs[0]
-		for _, ov := range vs[1:] {
-			v |= ov
-		}
-		return v
-	},
-}
-
-// stmt returns a prepared statement for the given SQL string, after
-// applying local template expansions. The statement is cached.
-func (s *DB) stmt(tpl string) stmt {
-	tpl = strings.TrimSpace(tpl)
-
-	// Fast concurrent lookup of cached statement
-	s.statementsMut.RLock()
-	stmt, ok := s.statements[tpl]
-	s.statementsMut.RUnlock()
-	if ok {
-		return stmt
-	}
-
-	// On miss, take the full lock, check again
-	s.statementsMut.Lock()
-	defer s.statementsMut.Unlock()
-	stmt, ok = s.statements[tpl]
-	if ok {
-		return stmt
-	}
-
-	// Apply template expansions
-	var sb strings.Builder
-	compTpl := template.Must(template.New("tpl").Funcs(tplFuncs).Parse(tpl))
-	if err := compTpl.Execute(&sb, s.tplInput); err != nil {
-		panic("bug: bad template: " + err.Error())
+func (s *DB) Close() error {
+	s.folderDBsMut.Lock()
+	defer s.folderDBsMut.Unlock()
+	for folder, fdb := range s.folderDBs {
+		fdb.Close()
+		delete(s.folderDBs, folder)
 	}
-
-	// Prepare and cache
-	stmt, err := s.sql.Preparex(sb.String())
-	if err != nil {
-		return failedStmt{err}
-	}
-	s.statements[tpl] = stmt
-	return stmt
-}
-
-type stmt interface {
-	Exec(args ...any) (sql.Result, error)
-	Get(dest any, args ...any) error
-	Queryx(args ...any) (*sqlx.Rows, error)
-	Select(dest any, args ...any) error
+	return wrap(s.baseDB.Close())
 }
-
-type failedStmt struct {
-	err error
-}
-
-func (f failedStmt) Exec(_ ...any) (sql.Result, error)   { return nil, f.err }
-func (f failedStmt) Get(_ any, _ ...any) error           { return f.err }
-func (f failedStmt) Queryx(_ ...any) (*sqlx.Rows, error) { return nil, f.err }
-func (f failedStmt) Select(_ any, _ ...any) error        { return f.err }

internal/db/sqlite/db_schema.go

@@ -1,88 +0,0 @@
-// Copyright (C) 2025 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at https://mozilla.org/MPL/2.0/.
-
-package sqlite
-
-import (
-	"embed"
-	"io/fs"
-	"strings"
-	"time"
-
-	"github.com/syncthing/syncthing/lib/build"
-)
-
-const currentSchemaVersion = 1
-
-//go:embed sql/**
-var embedded embed.FS
-
-func (s *DB) runScripts(glob string, filter ...func(s string) bool) error {
-	scripts, err := fs.Glob(embedded, glob)
-	if err != nil {
-		return wrap(err)
-	}
-
-	tx, err := s.sql.Begin()
-	if err != nil {
-		return wrap(err)
-	}
-	defer tx.Rollback() //nolint:errcheck
-
-nextScript:
-	for _, scr := range scripts {
-		for _, fn := range filter {
-			if !fn(scr) {
-				l.Debugln("Skipping script", scr)
-				continue nextScript
-			}
-		}
-		l.Debugln("Executing script", scr)
-		bs, err := fs.ReadFile(embedded, scr)
-		if err != nil {
-			return wrap(err, scr)
-		}
-		// SQLite requires one statement per exec, so we split the init
-		// files on lines containing only a semicolon and execute them
-		// separately. We require it on a separate line because there are
-		// also statement-internal semicolons in the triggers.
-		for _, stmt := range strings.Split(string(bs), "\n;") {
-			if _, err := tx.Exec(stmt); err != nil {
-				return wrap(err, stmt)
-			}
-		}
-	}
-
-	return wrap(tx.Commit())
-}
-
-type schemaVersion struct {
-	SchemaVersion    int
-	AppliedAt        int64
-	SyncthingVersion string
-}
-
-func (s *schemaVersion) AppliedTime() time.Time {
-	return time.Unix(0, s.AppliedAt)
-}
-
-func (s *DB) setAppliedSchemaVersion(ver int) error {
-	_, err := s.stmt(`
-		INSERT OR IGNORE INTO schemamigrations (schema_version, applied_at, syncthing_version)
-		VALUES (?, ?, ?)
-	`).Exec(ver, time.Now().UnixNano(), build.LongVersion)
-	return wrap(err)
-}
-
-func (s *DB) getAppliedSchemaVersion() (schemaVersion, error) {
-	var v schemaVersion
-	err := s.stmt(`
-		SELECT schema_version as schemaversion, applied_at as appliedat, syncthing_version as syncthingversion FROM schemamigrations
-		ORDER BY schema_version DESC
-		LIMIT 1
-	`).Get(&v)
-	return v, wrap(err)
-}

internal/db/sqlite/db_service.go

@@ -11,7 +11,9 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/jmoiron/sqlx"
 	"github.com/syncthing/syncthing/internal/db"
+	"github.com/thejerf/suture/v4"
 )
 
 const (
@@ -21,6 +23,10 @@ const (
 	minDeleteRetention     = 24 * time.Hour
 )
 
+func (s *DB) Service(maintenanceInterval time.Duration) suture.Service {
+	return newService(s, maintenanceInterval)
+}
+
 type Service struct {
 	sdb                 *DB
 	maintenanceInterval time.Duration
@@ -80,14 +86,25 @@ func (s *Service) periodic(ctx context.Context) error {
 	t1 := time.Now()
 	defer func() { l.Debugln("Periodic done in", time.Since(t1), "+", t1.Sub(t0)) }()
 
-	if err := s.garbageCollectOldDeletedLocked(); err != nil {
-		return wrap(err)
-	}
-	if err := s.garbageCollectBlocklistsAndBlocksLocked(ctx); err != nil {
-		return wrap(err)
-	}
+	tidy(ctx, s.sdb.sql)
 
-	conn, err := s.sdb.sql.Conn(ctx)
+	return wrap(s.sdb.forEachFolder(func(fdb *folderDB) error {
+		fdb.updateLock.Lock()
+		defer fdb.updateLock.Unlock()
+
+		if err := garbageCollectOldDeletedLocked(fdb); err != nil {
+			return wrap(err)
+		}
+		if err := garbageCollectBlocklistsAndBlocksLocked(ctx, fdb); err != nil {
+			return wrap(err)
+		}
+		tidy(ctx, fdb.sql)
+		return nil
+	}))
+}
+
+func tidy(ctx context.Context, db *sqlx.DB) error {
+	conn, err := db.Conn(ctx)
 	if err != nil {
 		return wrap(err)
 	}
@@ -95,35 +112,34 @@ func (s *Service) periodic(ctx context.Context) error {
 	_, _ = conn.ExecContext(ctx, `ANALYZE`)
 	_, _ = conn.ExecContext(ctx, `PRAGMA optimize`)
 	_, _ = conn.ExecContext(ctx, `PRAGMA incremental_vacuum`)
-	_, _ = conn.ExecContext(ctx, `PRAGMA journal_size_limit = 67108864`)
+	_, _ = conn.ExecContext(ctx, `PRAGMA journal_size_limit = 8388608`)
 	_, _ = conn.ExecContext(ctx, `PRAGMA wal_checkpoint(TRUNCATE)`)
-
 	return nil
 }
 
-func (s *Service) garbageCollectOldDeletedLocked() error {
-	if s.sdb.deleteRetention <= 0 {
-		l.Debugln("Delete retention is infinite, skipping cleanup")
+func garbageCollectOldDeletedLocked(fdb *folderDB) error {
+	if fdb.deleteRetention <= 0 {
+		l.Debugln(fdb.baseName, "delete retention is infinite, skipping cleanup")
 		return nil
 	}
 
 	// Remove deleted files that are marked as not needed (we have processed
 	// them) and they were deleted more than MaxDeletedFileAge ago.
-	l.Debugln("Forgetting deleted files older than", s.sdb.deleteRetention)
-	res, err := s.sdb.stmt(`
+	l.Debugln(fdb.baseName, "forgetting deleted files older than", fdb.deleteRetention)
+	res, err := fdb.stmt(`
 		DELETE FROM files
 		WHERE deleted AND modified < ? AND local_flags & {{.FlagLocalNeeded}} == 0
-	`).Exec(time.Now().Add(-s.sdb.deleteRetention).UnixNano())
+	`).Exec(time.Now().Add(-fdb.deleteRetention).UnixNano())
 	if err != nil {
 		return wrap(err)
 	}
 	if aff, err := res.RowsAffected(); err == nil {
-		l.Debugln("Removed old deleted file records:", aff)
+		l.Debugln(fdb.baseName, "removed old deleted file records:", aff)
 	}
 	return nil
 }
 
-func (s *Service) garbageCollectBlocklistsAndBlocksLocked(ctx context.Context) error {
+func garbageCollectBlocklistsAndBlocksLocked(ctx context.Context, fdb *folderDB) error {
 	// Remove all blocklists not referred to by any files and, by extension,
 	// any blocks not referred to by a blocklist. This is an expensive
 	// operation when run normally, especially if there are a lot of blocks
@@ -134,7 +150,7 @@ func (s *Service) garbageCollectBlocklistsAndBlocksLocked(ctx context.Context) e
 	// an explicit connection and disabling foreign keys before starting the
 	// transaction. We make sure to clean up on the way out.
 
-	conn, err := s.sdb.sql.Connx(ctx)
+	conn, err := fdb.sql.Connx(ctx)
 	if err != nil {
 		return wrap(err)
 	}
@@ -161,7 +177,7 @@ func (s *Service) garbageCollectBlocklistsAndBlocksLocked(ctx context.Context) e
 		return wrap(err, "delete blocklists")
 	} else if shouldDebug() {
 		rows, err := res.RowsAffected()
-		l.Debugln("Blocklist GC:", rows, err)
+		l.Debugln(fdb.baseName, "blocklist GC:", rows, err)
 	}
 
 	if res, err := tx.ExecContext(ctx, `
@@ -172,7 +188,7 @@ func (s *Service) garbageCollectBlocklistsAndBlocksLocked(ctx context.Context) e
 		return wrap(err, "delete blocks")
 	} else if shouldDebug() {
 		rows, err := res.RowsAffected()
-		l.Debugln("Blocks GC:", rows, err)
+		l.Debugln(fdb.baseName, "blocks GC:", rows, err)
 	}
 
 	return wrap(tx.Commit())

internal/db/sqlite/db_test.go

@@ -298,6 +298,7 @@ func TestBasics(t *testing.T) {
 			t.Fatal(err)
 		}
 		if len(folders) != 1 || folders[0] != folderID {
+			t.Log(folders)
 			t.Error("expected one folder")
 		}
 	})
@@ -1009,15 +1010,20 @@ func TestBlocklistGarbageCollection(t *testing.T) {
 
 	// There should exist three blockslists and six blocks
 
+	fdb, err := sdb.getFolderDB(folderID, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	var count int
-	if err := sdb.sql.Get(&count, `SELECT count(*) FROM blocklists`); err != nil {
+	if err := fdb.sql.Get(&count, `SELECT count(*) FROM blocklists`); err != nil {
 		t.Fatal(err)
 	}
 	if count != 3 {
 		t.Log(count)
 		t.Fatal("expected 3 blocklists")
 	}
-	if err := sdb.sql.Get(&count, `SELECT count(*) FROM blocks`); err != nil {
+	if err := fdb.sql.Get(&count, `SELECT count(*) FROM blocks`); err != nil {
 		t.Fatal(err)
 	}
 	if count != 6 {
@@ -1039,14 +1045,14 @@ func TestBlocklistGarbageCollection(t *testing.T) {
 
 	// There should exist two blockslists and four blocks
 
-	if err := sdb.sql.Get(&count, `SELECT count(*) FROM blocklists`); err != nil {
+	if err := fdb.sql.Get(&count, `SELECT count(*) FROM blocklists`); err != nil {
 		t.Fatal(err)
 	}
 	if count != 2 {
 		t.Log(count)
 		t.Error("expected 2 blocklists")
 	}
-	if err := sdb.sql.Get(&count, `SELECT count(*) FROM blocks`); err != nil {
+	if err := fdb.sql.Get(&count, `SELECT count(*) FROM blocks`); err != nil {
 		t.Fatal(err)
 	}
 	if count != 3 {
@@ -1078,7 +1084,7 @@ func TestInsertLargeFile(t *testing.T) {
 	// Verify all the blocks are here
 
 	for i, block := range files[0].Blocks {
-		bs, err := itererr.Collect(sdb.AllLocalBlocksWithHash(block.Hash))
+		bs, err := sdb.AllLocalBlocksWithHash(block.Hash)
 		if err != nil {
 			t.Fatal(err)
 		}

internal/db/sqlite/db_update.go

@@ -7,477 +7,38 @@
 package sqlite
 
 import (
-	"cmp"
-	"context"
 	"fmt"
+	"os"
 	"runtime"
-	"slices"
 	"strings"
-
-	"github.com/jmoiron/sqlx"
-	"github.com/syncthing/syncthing/internal/gen/dbproto"
-	"github.com/syncthing/syncthing/internal/itererr"
-	"github.com/syncthing/syncthing/lib/osutil"
-	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syncthing/syncthing/lib/sliceutil"
-	"google.golang.org/protobuf/proto"
-)
-
-const (
-	// Arbitrarily chosen values for checkpoint frequency....
-	updatePointsPerFile   = 100
-	updatePointsPerBlock  = 1
-	updatePointsThreshold = 250_000
 )
 
-func (s *DB) Update(folder string, device protocol.DeviceID, fs []protocol.FileInfo) error {
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err)
-	}
-	deviceIdx, err := s.deviceIdxLocked(device)
-	if err != nil {
-		return wrap(err)
-	}
-
-	tx, err := s.sql.BeginTxx(context.Background(), nil)
-	if err != nil {
-		return wrap(err)
-	}
-	defer tx.Rollback() //nolint:errcheck
-	txp := &txPreparedStmts{Tx: tx}
-
-	//nolint:sqlclosecheck
-	insertFileStmt, err := txp.Preparex(`
-		INSERT OR REPLACE INTO files (folder_idx, device_idx, remote_sequence, name, type, modified, size, version, deleted, invalid, local_flags, blocklist_hash)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
-		RETURNING sequence
-	`)
-	if err != nil {
-		return wrap(err, "prepare insert file")
-	}
-
-	//nolint:sqlclosecheck
-	insertFileInfoStmt, err := txp.Preparex(`
-		INSERT INTO fileinfos (sequence, fiprotobuf)
-		VALUES (?, ?)
-	`)
-	if err != nil {
-		return wrap(err, "prepare insert fileinfo")
-	}
-
-	//nolint:sqlclosecheck
-	insertBlockListStmt, err := txp.Preparex(`
-		INSERT OR IGNORE INTO blocklists (blocklist_hash, blprotobuf)
-		VALUES (?, ?)
-	`)
-	if err != nil {
-		return wrap(err, "prepare insert blocklist")
-	}
-
-	var prevRemoteSeq int64
-	for i, f := range fs {
-		f.Name = osutil.NormalizedFilename(f.Name)
-
-		var blockshash *[]byte
-		if len(f.Blocks) > 0 {
-			f.BlocksHash = protocol.BlocksHash(f.Blocks)
-			blockshash = &f.BlocksHash
-		} else {
-			f.BlocksHash = nil
-		}
-
-		if f.Type == protocol.FileInfoTypeDirectory {
-			f.Size = 128 // synthetic directory size
-		}
-
-		// Insert the file.
-		//
-		// If it is a remote file, set remote_sequence otherwise leave it at
-		// null. Returns the new local sequence.
-		var remoteSeq *int64
-		if device != protocol.LocalDeviceID {
-			if i > 0 && f.Sequence == prevRemoteSeq {
-				return fmt.Errorf("duplicate remote sequence number %d", prevRemoteSeq)
-			}
-			prevRemoteSeq = f.Sequence
-			remoteSeq = &f.Sequence
-		}
-		var localSeq int64
-		if err := insertFileStmt.Get(&localSeq, folderIdx, deviceIdx, remoteSeq, f.Name, f.Type, f.ModTime().UnixNano(), f.Size, f.Version.String(), f.IsDeleted(), f.IsInvalid(), f.LocalFlags, blockshash); err != nil {
-			return wrap(err, "insert file")
-		}
-
-		if len(f.Blocks) > 0 {
-			// Indirect the block list
-			blocks := sliceutil.Map(f.Blocks, protocol.BlockInfo.ToWire)
-			bs, err := proto.Marshal(&dbproto.BlockList{Blocks: blocks})
-			if err != nil {
-				return wrap(err, "marshal blocklist")
-			}
-			if _, err := insertBlockListStmt.Exec(f.BlocksHash, bs); err != nil {
-				return wrap(err, "insert blocklist")
-			}
-
-			if device == protocol.LocalDeviceID {
-				// Insert all blocks
-				if err := s.insertBlocksLocked(txp, f.BlocksHash, f.Blocks); err != nil {
-					return wrap(err, "insert blocks")
-				}
-			}
-
-			f.Blocks = nil
-		}
-
-		// Insert the fileinfo
-		if device == protocol.LocalDeviceID {
-			f.Sequence = localSeq
-		}
-		bs, err := proto.Marshal(f.ToWire(true))
-		if err != nil {
-			return wrap(err, "marshal fileinfo")
-		}
-		if _, err := insertFileInfoStmt.Exec(localSeq, bs); err != nil {
-			return wrap(err, "insert fileinfo")
-		}
-
-		// Update global and need
-		if err := s.recalcGlobalForFile(txp, folderIdx, f.Name); err != nil {
-			return wrap(err)
-		}
-	}
-
-	if err := tx.Commit(); err != nil {
-		return wrap(err)
-	}
-
-	s.periodicCheckpointLocked(fs)
-	return nil
-}
-
 func (s *DB) DropFolder(folder string) error {
+	s.folderDBsMut.Lock()
+	defer s.folderDBsMut.Unlock()
 	s.updateLock.Lock()
 	defer s.updateLock.Unlock()
 	_, err := s.stmt(`
 		DELETE FROM folders
 		WHERE folder_id = ?
 	`).Exec(folder)
-	return wrap(err)
-}
-
-func (s *DB) DropDevice(device protocol.DeviceID) error {
-	if device == protocol.LocalDeviceID {
-		panic("bug: cannot drop local device")
-	}
-
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-
-	deviceIdx, err := s.deviceIdxLocked(device)
-	if err != nil {
-		return wrap(err)
-	}
-
-	tx, err := s.sql.BeginTxx(context.Background(), nil)
-	if err != nil {
-		return wrap(err)
+	if fdb, ok := s.folderDBs[folder]; ok {
+		fdb.Close()
+		_ = os.Remove(fdb.path)
+		_ = os.Remove(fdb.path + "-wal")
+		_ = os.Remove(fdb.path + "-shm")
+		delete(s.folderDBs, folder)
 	}
-	defer tx.Rollback() //nolint:errcheck
-	txp := &txPreparedStmts{Tx: tx}
-
-	// Find all folders where the device is involved
-	var folderIdxs []int64
-	if err := tx.Select(&folderIdxs, `
-		SELECT folder_idx
-		FROM counts
-		WHERE device_idx = ? AND count > 0
-		GROUP BY folder_idx
-	`, deviceIdx); err != nil {
-		return wrap(err)
-	}
-
-	// Drop the device, which cascades to delete all files etc for it
-	if _, err := tx.Exec(`DELETE FROM devices WHERE device_id = ?`, device.String()); err != nil {
-		return wrap(err)
-	}
-
-	// Recalc the globals for all affected folders
-	for _, idx := range folderIdxs {
-		if err := s.recalcGlobalForFolder(txp, idx); err != nil {
-			return wrap(err)
-		}
-	}
-
-	return wrap(tx.Commit())
-}
-
-func (s *DB) DropAllFiles(folder string, device protocol.DeviceID) error {
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-
-	// This is a two part operation, first dropping all the files and then
-	// recalculating the global state for the entire folder.
-
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err)
-	}
-	deviceIdx, err := s.deviceIdxLocked(device)
-	if err != nil {
-		return wrap(err)
-	}
-
-	tx, err := s.sql.BeginTxx(context.Background(), nil)
-	if err != nil {
-		return wrap(err)
-	}
-	defer tx.Rollback() //nolint:errcheck
-	txp := &txPreparedStmts{Tx: tx}
-
-	// Drop all the file entries
-
-	result, err := tx.Exec(`
-		DELETE FROM files
-		WHERE folder_idx = ? AND device_idx = ?
-	`, folderIdx, deviceIdx)
-	if err != nil {
-		return wrap(err)
-	}
-	if n, err := result.RowsAffected(); err == nil && n == 0 {
-		// The delete affected no rows, so we don't need to redo the entire
-		// global/need calculation.
-		return wrap(tx.Commit())
-	}
-
-	// Recalc global for the entire folder
-
-	if err := s.recalcGlobalForFolder(txp, folderIdx); err != nil {
-		return wrap(err)
-	}
-	return wrap(tx.Commit())
-}
-
-func (s *DB) DropFilesNamed(folder string, device protocol.DeviceID, names []string) error {
-	for i := range names {
-		names[i] = osutil.NormalizedFilename(names[i])
-	}
-
-	s.updateLock.Lock()
-	defer s.updateLock.Unlock()
-
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err)
-	}
-	deviceIdx, err := s.deviceIdxLocked(device)
-	if err != nil {
-		return wrap(err)
-	}
-
-	tx, err := s.sql.BeginTxx(context.Background(), nil)
-	if err != nil {
-		return wrap(err)
-	}
-	defer tx.Rollback() //nolint:errcheck
-	txp := &txPreparedStmts{Tx: tx}
-
-	// Drop the named files
-
-	query, args, err := sqlx.In(`
-		DELETE FROM files
-		WHERE folder_idx = ? AND device_idx = ? AND name IN (?)
-	`, folderIdx, deviceIdx, names)
-	if err != nil {
-		return wrap(err)
-	}
-	if _, err := tx.Exec(query, args...); err != nil {
-		return wrap(err)
-	}
-
-	// Recalc globals for the named files
-
-	for _, name := range names {
-		if err := s.recalcGlobalForFile(txp, folderIdx, name); err != nil {
-			return wrap(err)
-		}
-	}
-
-	return wrap(tx.Commit())
-}
-
-func (*DB) insertBlocksLocked(tx *txPreparedStmts, blocklistHash []byte, blocks []protocol.BlockInfo) error {
-	if len(blocks) == 0 {
-		return nil
-	}
-	bs := make([]map[string]any, len(blocks))
-	for i, b := range blocks {
-		bs[i] = map[string]any{
-			"hash":           b.Hash,
-			"blocklist_hash": blocklistHash,
-			"idx":            i,
-			"offset":         b.Offset,
-			"size":           b.Size,
-		}
-	}
-
-	// Very large block lists (>8000 blocks) result in "too many variables"
-	// error. Chunk it to a reasonable size.
-	for chunk := range slices.Chunk(bs, 1000) {
-		if _, err := tx.NamedExec(`
-			INSERT OR IGNORE INTO blocks (hash, blocklist_hash, idx, offset, size)
-			VALUES (:hash, :blocklist_hash, :idx, :offset, :size)
-		`, chunk); err != nil {
-			return wrap(err)
-		}
-	}
-	return nil
-}
-
-func (s *DB) recalcGlobalForFolder(txp *txPreparedStmts, folderIdx int64) error {
-	// Select files where there is no global, those are the ones we need to
-	// recalculate.
-	//nolint:sqlclosecheck
-	namesStmt, err := txp.Preparex(`
-		SELECT f.name FROM files f
-		WHERE f.folder_idx = ? AND NOT EXISTS (
-			SELECT 1 FROM files g
-			WHERE g.folder_idx = ? AND g.name = f.name AND g.local_flags & ? != 0
-		)
-		GROUP BY name
-	`)
-	if err != nil {
-		return wrap(err)
-	}
-	rows, err := namesStmt.Queryx(folderIdx, folderIdx, protocol.FlagLocalGlobal)
-	if err != nil {
-		return wrap(err)
-	}
-	defer rows.Close()
-	for rows.Next() {
-		var name string
-		if err := rows.Scan(&name); err != nil {
-			return wrap(err)
-		}
-		if err := s.recalcGlobalForFile(txp, folderIdx, name); err != nil {
-			return wrap(err)
-		}
-	}
-	return wrap(rows.Err())
-}
-
-func (s *DB) recalcGlobalForFile(txp *txPreparedStmts, folderIdx int64, file string) error {
-	//nolint:sqlclosecheck
-	selStmt, err := txp.Preparex(`
-		SELECT name, folder_idx, device_idx, sequence, modified, version, deleted, invalid, local_flags FROM files
-		WHERE folder_idx = ? AND name = ?
-	`)
-	if err != nil {
-		return wrap(err)
-	}
-	es, err := itererr.Collect(iterStructs[fileRow](selStmt.Queryx(folderIdx, file)))
-	if err != nil {
-		return wrap(err)
-	}
-	if len(es) == 0 {
-		// shouldn't happen
-		return nil
-	}
-
-	// Sort the entries; the global entry is at the head of the list
-	slices.SortFunc(es, fileRow.Compare)
-
-	// The global version is the first one in the list that is not invalid,
-	// or just the first one in the list if all are invalid.
-	var global fileRow
-	globIdx := slices.IndexFunc(es, func(e fileRow) bool { return !e.Invalid })
-	if globIdx < 0 {
-		globIdx = 0
-	}
-	global = es[globIdx]
-
-	// We "have" the file if the position in the list of versions is at the
-	// global version or better, or if the version is the same as the global
-	// file (we might be further down the list due to invalid flags), or if
-	// the global is deleted and we don't have it at all...
-	localIdx := slices.IndexFunc(es, func(e fileRow) bool { return e.DeviceIdx == s.localDeviceIdx })
-	hasLocal := localIdx >= 0 && localIdx <= globIdx || // have a better or equal version
-		localIdx >= 0 && es[localIdx].Version.Equal(global.Version.Vector) || // have an equal version but invalid/ignored
-		localIdx < 0 && global.Deleted // missing it, but the global is also deleted
-
-	// Set the global flag on the global entry. Set the need flag if the
-	// local device needs this file, unless it's invalid.
-	global.LocalFlags |= protocol.FlagLocalGlobal
-	if hasLocal || global.Invalid {
-		global.LocalFlags &= ^protocol.FlagLocalNeeded
-	} else {
-		global.LocalFlags |= protocol.FlagLocalNeeded
-	}
-	//nolint:sqlclosecheck
-	upStmt, err := txp.Prepare(`
-		UPDATE files SET local_flags = ?
-		WHERE folder_idx = ? AND device_idx = ? AND sequence = ?
-	`)
-	if err != nil {
-		return wrap(err)
-	}
-	if _, err := upStmt.Exec(global.LocalFlags, global.FolderIdx, global.DeviceIdx, global.Sequence); err != nil {
-		return wrap(err)
-	}
-
-	// Clear the need and global flags on all other entries
-	//nolint:sqlclosecheck
-	upStmt, err = txp.Prepare(`
-		UPDATE files SET local_flags = local_flags & ?
-		WHERE folder_idx = ? AND name = ? AND sequence != ? AND local_flags & ? != 0
-	`)
-	if err != nil {
-		return wrap(err)
-	}
-	if _, err := upStmt.Exec(^(protocol.FlagLocalNeeded | protocol.FlagLocalGlobal), folderIdx, global.Name, global.Sequence, protocol.FlagLocalNeeded|protocol.FlagLocalGlobal); err != nil {
-		return wrap(err)
-	}
-
-	return nil
+	return wrap(err)
 }
 
-func (s *DB) folderIdxLocked(folderID string) (int64, error) {
-	if _, err := s.stmt(`
-		INSERT OR IGNORE INTO folders(folder_id)
-		VALUES (?)
-	`).Exec(folderID); err != nil {
-		return 0, wrap(err)
-	}
-	var idx int64
-	if err := s.stmt(`
-		SELECT idx FROM folders
-		WHERE folder_id = ?
-	`).Get(&idx, folderID); err != nil {
-		return 0, wrap(err)
-	}
-
-	return idx, nil
-}
-
-func (s *DB) deviceIdxLocked(deviceID protocol.DeviceID) (int64, error) {
-	devStr := deviceID.String()
-	if _, err := s.stmt(`
-		INSERT OR IGNORE INTO devices(device_id)
-		VALUES (?)
-	`).Exec(devStr); err != nil {
-		return 0, wrap(err)
-	}
-	var idx int64
-	if err := s.stmt(`
-		SELECT idx FROM devices
-		WHERE device_id = ?
-	`).Get(&idx, devStr); err != nil {
-		return 0, wrap(err)
-	}
-
-	return idx, nil
+func (s *DB) ListFolders() ([]string, error) {
+	var res []string
+	err := s.stmt(`
+		SELECT folder_id FROM folders
+		ORDER BY folder_id
+	`).Select(&res)
+	return res, wrap(err)
 }
 
 // wrap returns the error wrapped with the calling function name and
@@ -507,94 +68,3 @@ func wrap(err error, context ...string) error {
 
 	return fmt.Errorf("%s: %w", prefix, err)
 }
-
-type fileRow struct {
-	Name       string
-	Version    dbVector
-	FolderIdx  int64 `db:"folder_idx"`
-	DeviceIdx  int64 `db:"device_idx"`
-	Sequence   int64
-	Modified   int64
-	Size       int64
-	LocalFlags int64 `db:"local_flags"`
-	Deleted    bool
-	Invalid    bool
-}
-
-func (e fileRow) Compare(other fileRow) int {
-	// From FileInfo.WinsConflict
-	vc := e.Version.Vector.Compare(other.Version.Vector)
-	switch vc {
-	case protocol.Equal:
-		if e.Invalid != other.Invalid {
-			if e.Invalid {
-				return 1
-			}
-			return -1
-		}
-
-		// Compare the device ID index, lower is better. This is only
-		// deterministic to the extent that LocalDeviceID will always be the
-		// lowest one, order between remote devices is random (and
-		// irrelevant).
-		return cmp.Compare(e.DeviceIdx, other.DeviceIdx)
-	case protocol.Greater: // we are newer
-		return -1
-	case protocol.Lesser: // we are older
-		return 1
-	case protocol.ConcurrentGreater, protocol.ConcurrentLesser: // there is a conflict
-		if e.Invalid != other.Invalid {
-			if e.Invalid { // we are invalid, we lose
-				return 1
-			}
-			return -1 // they are invalid, we win
-		}
-		if e.Deleted != other.Deleted {
-			if e.Deleted { // we are deleted, we lose
-				return 1
-			}
-			return -1 // they are deleted, we win
-		}
-		if d := cmp.Compare(e.Modified, other.Modified); d != 0 {
-			return -d // positive d means we were newer, so we win (negative return)
-		}
-		if vc == protocol.ConcurrentGreater {
-			return -1 // we have a better device ID, we win
-		}
-		return 1 // they win
-	default:
-		return 0
-	}
-}
-
-func (s *DB) periodicCheckpointLocked(fs []protocol.FileInfo) {
-	// Induce periodic checkpoints. We add points for each file and block,
-	// and checkpoint when we've written more than a threshold of points.
-	// This ensures we do not go too long without a checkpoint, while also
-	// not doing it incessantly for every update.
-	s.updatePoints += updatePointsPerFile * len(fs)
-	for _, f := range fs {
-		s.updatePoints += len(f.Blocks) * updatePointsPerBlock
-	}
-	if s.updatePoints > updatePointsThreshold {
-		conn, err := s.sql.Conn(context.Background())
-		if err != nil {
-			l.Debugln("conn:", err)
-			return
-		}
-		defer conn.Close()
-		if _, err := conn.ExecContext(context.Background(), `PRAGMA journal_size_limit = 67108864`); err != nil {
-			l.Debugln("PRAGMA journal_size_limit:", err)
-		}
-		row := conn.QueryRowContext(context.Background(), `PRAGMA wal_checkpoint(RESTART)`)
-		var res, modified, moved int
-		if row.Err() != nil {
-			l.Debugln("PRAGMA wal_checkpoint(RESTART):", err)
-		} else if err := row.Scan(&res, &modified, &moved); err != nil {
-			l.Debugln("PRAGMA wal_checkpoint(RESTART) (scan):", err)
-		} else {
-			l.Debugln("checkpoint at", s.updatePoints, "returned", res, modified, moved)
-		}
-		s.updatePoints = 0
-	}
-}

internal/db/sqlite/db_counts.go → internal/db/sqlite/folderdb_counts.go

@@ -19,95 +19,89 @@ type countsRow struct {
 	LocalFlags int64 `db:"local_flags"`
 }
 
-func (s *DB) CountLocal(folder string, device protocol.DeviceID) (db.Counts, error) {
+func (s *folderDB) CountLocal(device protocol.DeviceID) (db.Counts, error) {
 	var res []countsRow
 	if err := s.stmt(`
 		SELECT s.type, s.count, s.size, s.local_flags, s.deleted FROM counts s
-		INNER JOIN folders o ON o.idx = s.folder_idx
 		INNER JOIN devices d ON d.idx = s.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ? AND s.local_flags & {{.FlagLocalIgnored}} = 0
-	`).Select(&res, folder, device.String()); err != nil {
+		WHERE d.device_id = ? AND s.local_flags & {{.FlagLocalIgnored}} = 0
+	`).Select(&res, device.String()); err != nil {
 		return db.Counts{}, wrap(err)
 	}
 	return summarizeCounts(res), nil
 }
 
-func (s *DB) CountNeed(folder string, device protocol.DeviceID) (db.Counts, error) {
+func (s *folderDB) CountNeed(device protocol.DeviceID) (db.Counts, error) {
 	if device == protocol.LocalDeviceID {
-		return s.needSizeLocal(folder)
+		return s.needSizeLocal()
 	}
-	return s.needSizeRemote(folder, device)
+	return s.needSizeRemote(device)
 }
 
-func (s *DB) CountGlobal(folder string) (db.Counts, error) {
+func (s *folderDB) CountGlobal() (db.Counts, error) {
 	// Exclude ignored and receive-only changed files from the global count
 	// (legacy expectation? it's a bit weird since those files can in fact
 	// be global and you can get them with GetGlobal etc.)
 	var res []countsRow
 	err := s.stmt(`
 		SELECT s.type, s.count, s.size, s.local_flags, s.deleted FROM counts s
-		INNER JOIN folders o ON o.idx = s.folder_idx
-		WHERE o.folder_id = ? AND s.local_flags & {{.FlagLocalGlobal}} != 0 AND s.local_flags & {{or .FlagLocalReceiveOnly .FlagLocalIgnored}} = 0
-	`).Select(&res, folder)
+		WHERE s.local_flags & {{.FlagLocalGlobal}} != 0 AND s.local_flags & {{or .FlagLocalReceiveOnly .FlagLocalIgnored}} = 0
+	`).Select(&res)
 	if err != nil {
 		return db.Counts{}, wrap(err)
 	}
 	return summarizeCounts(res), nil
 }
 
-func (s *DB) CountReceiveOnlyChanged(folder string) (db.Counts, error) {
+func (s *folderDB) CountReceiveOnlyChanged() (db.Counts, error) {
 	var res []countsRow
 	err := s.stmt(`
 		SELECT s.type, s.count, s.size, s.local_flags, s.deleted FROM counts s
-		INNER JOIN folders o ON o.idx = s.folder_idx
-		WHERE o.folder_id = ? AND local_flags & {{.FlagLocalReceiveOnly}} != 0
-	`).Select(&res, folder)
+		WHERE local_flags & {{.FlagLocalReceiveOnly}} != 0
+	`).Select(&res)
 	if err != nil {
 		return db.Counts{}, wrap(err)
 	}
 	return summarizeCounts(res), nil
 }
 
-func (s *DB) needSizeLocal(folder string) (db.Counts, error) {
+func (s *folderDB) needSizeLocal() (db.Counts, error) {
 	// The need size for the local device is the sum of entries with the
 	// need bit set.
 	var res []countsRow
 	err := s.stmt(`
 		SELECT s.type, s.count, s.size, s.local_flags, s.deleted FROM counts s
-		INNER JOIN folders o ON o.idx = s.folder_idx
-		WHERE o.folder_id = ? AND s.local_flags & {{.FlagLocalNeeded}} != 0
-	`).Select(&res, folder)
+		WHERE s.local_flags & {{.FlagLocalNeeded}} != 0
+	`).Select(&res)
 	if err != nil {
 		return db.Counts{}, wrap(err)
 	}
 	return summarizeCounts(res), nil
 }
 
-func (s *DB) needSizeRemote(folder string, device protocol.DeviceID) (db.Counts, error) {
+func (s *folderDB) needSizeRemote(device protocol.DeviceID) (db.Counts, error) {
 	var res []countsRow
 	// See neededGlobalFilesRemote for commentary as that is the same query without summing
 	if err := s.stmt(`
 		SELECT g.type, count(*) as count, sum(g.size) as size, g.local_flags, g.deleted FROM files g
-		INNER JOIN folders o ON o.idx = g.folder_idx
-		WHERE o.folder_id = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND NOT g.deleted AND NOT g.invalid AND NOT EXISTS (
+		WHERE g.local_flags & {{.FlagLocalGlobal}} != 0 AND NOT g.deleted AND NOT g.invalid AND NOT EXISTS (
 			SELECT 1 FROM FILES f
 			INNER JOIN devices d ON d.idx = f.device_idx
-			WHERE f.name = g.name AND f.version = g.version AND f.folder_idx = g.folder_idx AND d.device_id = ?
+			WHERE f.name = g.name AND f.version = g.version AND d.device_id = ?
 		)
 		GROUP BY g.type, g.local_flags, g.deleted
 
 		UNION ALL
 
 		SELECT g.type, count(*) as count, sum(g.size) as size, g.local_flags, g.deleted FROM files g
-		INNER JOIN folders o ON o.idx = g.folder_idx
-		WHERE o.folder_id = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND g.deleted AND NOT g.invalid AND EXISTS (
+		WHERE g.local_flags & {{.FlagLocalGlobal}} != 0 AND g.deleted AND NOT g.invalid AND EXISTS (
 			SELECT 1 FROM FILES f
 			INNER JOIN devices d ON d.idx = f.device_idx
-			WHERE f.name = g.name AND f.folder_idx = g.folder_idx AND d.device_id = ? AND NOT f.deleted
+			WHERE f.name = g.name AND d.device_id = ? AND NOT f.deleted
 		)
 		GROUP BY g.type, g.local_flags, g.deleted
-	`).Select(&res, folder, device.String(),
-		folder, device.String()); err != nil {
+	`).Select(&res, device.String(),
+		device.String()); err != nil {
 		return db.Counts{}, wrap(err)
 	}
 

internal/db/sqlite/db_global.go → internal/db/sqlite/folderdb_global.go

@@ -19,7 +19,7 @@ import (
 	"github.com/syncthing/syncthing/lib/protocol"
 )
 
-func (s *DB) GetGlobalFile(folder string, file string) (protocol.FileInfo, bool, error) {
+func (s *folderDB) GetGlobalFile(file string) (protocol.FileInfo, bool, error) {
 	file = osutil.NormalizedFilename(file)
 
 	var ind indirectFI
@@ -27,9 +27,8 @@ func (s *DB) GetGlobalFile(folder string, file string) (protocol.FileInfo, bool,
 		SELECT fi.fiprotobuf, bl.blprotobuf FROM fileinfos fi
 		INNER JOIN files f on fi.sequence = f.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = f.blocklist_hash
-		INNER JOIN folders o ON o.idx = f.folder_idx
-		WHERE o.folder_id = ? AND f.name = ? AND f.local_flags & {{.FlagLocalGlobal}} != 0
-	`).Get(&ind, folder, file)
+		WHERE f.name = ? AND f.local_flags & {{.FlagLocalGlobal}} != 0
+	`).Get(&ind, file)
 	if errors.Is(err, sql.ErrNoRows) {
 		return protocol.FileInfo{}, false, nil
 	}
@@ -43,18 +42,17 @@ func (s *DB) GetGlobalFile(folder string, file string) (protocol.FileInfo, bool,
 	return fi, true, nil
 }
 
-func (s *DB) GetGlobalAvailability(folder, file string) ([]protocol.DeviceID, error) {
+func (s *folderDB) GetGlobalAvailability(file string) ([]protocol.DeviceID, error) {
 	file = osutil.NormalizedFilename(file)
 
 	var devStrs []string
 	err := s.stmt(`
 		SELECT d.device_id FROM files f
 		INNER JOIN devices d ON d.idx = f.device_idx
-		INNER JOIN folders o ON o.idx = f.folder_idx
-		INNER JOIN files g ON f.folder_idx = g.folder_idx AND g.version = f.version AND g.name = f.name
-		WHERE o.folder_id = ? AND g.name = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND f.device_idx != {{.LocalDeviceIdx}}
+		INNER JOIN files g ON g.version = f.version AND g.name = f.name
+		WHERE g.name = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND f.device_idx != {{.LocalDeviceIdx}}
 		ORDER BY d.device_id
-	`).Select(&devStrs, folder, file)
+	`).Select(&devStrs, file)
 	if errors.Is(err, sql.ErrNoRows) {
 		return nil, nil
 	}
@@ -74,22 +72,21 @@ func (s *DB) GetGlobalAvailability(folder, file string) ([]protocol.DeviceID, er
 	return devs, nil
 }
 
-func (s *DB) AllGlobalFiles(folder string) (iter.Seq[db.FileMetadata], func() error) {
+func (s *folderDB) AllGlobalFiles() (iter.Seq[db.FileMetadata], func() error) {
 	it, errFn := iterStructs[db.FileMetadata](s.stmt(`
 		SELECT f.sequence, f.name, f.type, f.modified as modnanos, f.size, f.deleted, f.invalid, f.local_flags as localflags FROM files f
-		INNER JOIN folders o ON o.idx = f.folder_idx
-		WHERE o.folder_id = ? AND f.local_flags & {{.FlagLocalGlobal}} != 0
+		WHERE f.local_flags & {{.FlagLocalGlobal}} != 0
 		ORDER BY f.name
-	`).Queryx(folder))
+	`).Queryx())
 	return itererr.Map(it, errFn, func(m db.FileMetadata) (db.FileMetadata, error) {
 		m.Name = osutil.NativeFilename(m.Name)
 		return m, nil
 	})
 }
 
-func (s *DB) AllGlobalFilesPrefix(folder string, prefix string) (iter.Seq[db.FileMetadata], func() error) {
+func (s *folderDB) AllGlobalFilesPrefix(prefix string) (iter.Seq[db.FileMetadata], func() error) {
 	if prefix == "" {
-		return s.AllGlobalFiles(folder)
+		return s.AllGlobalFiles()
 	}
 
 	prefix = osutil.NormalizedFilename(prefix)
@@ -97,17 +94,16 @@ func (s *DB) AllGlobalFilesPrefix(folder string, prefix string) (iter.Seq[db.Fil
 
 	it, errFn := iterStructs[db.FileMetadata](s.stmt(`
 		SELECT f.sequence, f.name, f.type, f.modified as modnanos, f.size, f.deleted, f.invalid, f.local_flags as localflags FROM files f
-		INNER JOIN folders o ON o.idx = f.folder_idx
-		WHERE o.folder_id = ? AND f.name >= ? AND f.name < ? AND f.local_flags & {{.FlagLocalGlobal}} != 0
+		WHERE f.name >= ? AND f.name < ? AND f.local_flags & {{.FlagLocalGlobal}} != 0
 		ORDER BY f.name
-	`).Queryx(folder, prefix, end))
+	`).Queryx(prefix, end))
 	return itererr.Map(it, errFn, func(m db.FileMetadata) (db.FileMetadata, error) {
 		m.Name = osutil.NativeFilename(m.Name)
 		return m, nil
 	})
 }
 
-func (s *DB) AllNeededGlobalFiles(folder string, device protocol.DeviceID, order config.PullOrder, limit, offset int) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) AllNeededGlobalFiles(device protocol.DeviceID, order config.PullOrder, limit, offset int) (iter.Seq[protocol.FileInfo], func() error) {
 	var selectOpts string
 	switch order {
 	case config.PullOrderRandom:
@@ -132,25 +128,24 @@ func (s *DB) AllNeededGlobalFiles(folder string, device protocol.DeviceID, order
 	}
 
 	if device == protocol.LocalDeviceID {
-		return s.neededGlobalFilesLocal(folder, selectOpts)
+		return s.neededGlobalFilesLocal(selectOpts)
 	}
 
-	return s.neededGlobalFilesRemote(folder, device, selectOpts)
+	return s.neededGlobalFilesRemote(device, selectOpts)
 }
 
-func (s *DB) neededGlobalFilesLocal(folder, selectOpts string) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) neededGlobalFilesLocal(selectOpts string) (iter.Seq[protocol.FileInfo], func() error) {
 	// Select all the non-ignored files with the need bit set.
 	it, errFn := iterStructs[indirectFI](s.stmt(`
 		SELECT fi.fiprotobuf, bl.blprotobuf, g.name, g.size, g.modified FROM fileinfos fi
 		INNER JOIN files g on fi.sequence = g.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = g.blocklist_hash
-		INNER JOIN folders o ON o.idx = g.folder_idx
-		WHERE o.folder_id = ? AND g.local_flags & {{.FlagLocalIgnored}} = 0 AND g.local_flags & {{.FlagLocalNeeded}} != 0
-	` + selectOpts).Queryx(folder))
+		WHERE g.local_flags & {{.FlagLocalIgnored}} = 0 AND g.local_flags & {{.FlagLocalNeeded}} != 0
+	` + selectOpts).Queryx())
 	return itererr.Map(it, errFn, indirectFI.FileInfo)
 }
 
-func (s *DB) neededGlobalFilesRemote(folder string, device protocol.DeviceID, selectOpts string) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) neededGlobalFilesRemote(device protocol.DeviceID, selectOpts string) (iter.Seq[protocol.FileInfo], func() error) {
 	// Select:
 	//
 	// - all the valid, non-deleted global files that don't have a corresponding
@@ -163,11 +158,10 @@ func (s *DB) neededGlobalFilesRemote(folder string, device protocol.DeviceID, se
 		SELECT fi.fiprotobuf, bl.blprotobuf, g.name, g.size, g.modified FROM fileinfos fi
 		INNER JOIN files g on fi.sequence = g.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = g.blocklist_hash
-		INNER JOIN folders o ON o.idx = g.folder_idx
-		WHERE o.folder_id = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND NOT g.deleted AND NOT g.invalid AND NOT EXISTS (
+		WHERE g.local_flags & {{.FlagLocalGlobal}} != 0 AND NOT g.deleted AND NOT g.invalid AND NOT EXISTS (
 			SELECT 1 FROM FILES f
 			INNER JOIN devices d ON d.idx = f.device_idx
-			WHERE f.name = g.name AND f.version = g.version AND f.folder_idx = g.folder_idx AND d.device_id = ?
+			WHERE f.name = g.name AND f.version = g.version AND d.device_id = ?
 		)
 
 		UNION ALL
@@ -175,15 +169,14 @@ func (s *DB) neededGlobalFilesRemote(folder string, device protocol.DeviceID, se
 		SELECT fi.fiprotobuf, bl.blprotobuf, g.name, g.size, g.modified FROM fileinfos fi
 		INNER JOIN files g on fi.sequence = g.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = g.blocklist_hash
-		INNER JOIN folders o ON o.idx = g.folder_idx
-		WHERE o.folder_id = ? AND g.local_flags & {{.FlagLocalGlobal}} != 0 AND g.deleted AND NOT g.invalid AND EXISTS (
+		WHERE g.local_flags & {{.FlagLocalGlobal}} != 0 AND g.deleted AND NOT g.invalid AND EXISTS (
 			SELECT 1 FROM FILES f
 			INNER JOIN devices d ON d.idx = f.device_idx
-			WHERE f.name = g.name AND f.folder_idx = g.folder_idx AND d.device_id = ? AND NOT f.deleted
+			WHERE f.name = g.name AND d.device_id = ? AND NOT f.deleted
 		)
 	`+selectOpts).Queryx(
-		folder, device.String(),
-		folder, device.String(),
+		device.String(),
+		device.String(),
 	))
 	return itererr.Map(it, errFn, indirectFI.FileInfo)
 }

internal/db/sqlite/db_indexid.go → internal/db/sqlite/folderdb_indexid.go

@@ -16,16 +16,15 @@ import (
 	"github.com/syncthing/syncthing/lib/protocol"
 )
 
-func (s *DB) GetIndexID(folder string, device protocol.DeviceID) (protocol.IndexID, error) {
+func (s *folderDB) GetIndexID(device protocol.DeviceID) (protocol.IndexID, error) {
 	// Try a fast read-only query to begin with. If it does not find the ID
 	// we'll do the full thing under a lock.
 	var indexID string
 	if err := s.stmt(`
 		SELECT i.index_id FROM indexids i
-		INNER JOIN folders o ON o.idx  = i.folder_idx
 		INNER JOIN devices d ON d.idx  = i.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ?
-	`).Get(&indexID, folder, device.String()); err == nil && indexID != "" {
+		WHERE d.device_id = ?
+	`).Get(&indexID, device.String()); err == nil && indexID != "" {
 		idx, err := indexIDFromHex(indexID)
 		return idx, wrap(err, "select")
 	}
@@ -40,14 +39,9 @@ func (s *DB) GetIndexID(folder string, device protocol.DeviceID) (protocol.Index
 
 	// We are now operating only for the local device ID
 
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return 0, wrap(err)
-	}
-
 	if err := s.stmt(`
-		SELECT index_id FROM indexids WHERE folder_idx = ? AND device_idx = {{.LocalDeviceIdx}}
-	`).Get(&indexID, folderIdx); err != nil && !errors.Is(err, sql.ErrNoRows) {
+		SELECT index_id FROM indexids WHERE device_idx = {{.LocalDeviceIdx}}
+	`).Get(&indexID); err != nil && !errors.Is(err, sql.ErrNoRows) {
 		return 0, wrap(err, "select local")
 	}
 
@@ -57,11 +51,11 @@ func (s *DB) GetIndexID(folder string, device protocol.DeviceID) (protocol.Index
 		// any.
 		id := protocol.NewIndexID()
 		if _, err := s.stmt(`
-			INSERT INTO indexids (folder_idx, device_idx, index_id, sequence)
-				SELECT ?, {{.LocalDeviceIdx}}, ?, COALESCE(MAX(sequence), 0) FROM files
-				WHERE folder_idx = ? AND device_idx = {{.LocalDeviceIdx}}
+			INSERT INTO indexids (device_idx, index_id, sequence)
+				SELECT {{.LocalDeviceIdx}}, ?, COALESCE(MAX(sequence), 0) FROM files
+				WHERE device_idx = {{.LocalDeviceIdx}}
 			ON CONFLICT DO UPDATE SET index_id = ?
-		`).Exec(folderIdx, indexIDToHex(id), folderIdx, indexIDToHex(id)); err != nil {
+		`).Exec(indexIDToHex(id), indexIDToHex(id)); err != nil {
 			return 0, wrap(err, "insert")
 		}
 		return id, nil
@@ -70,42 +64,37 @@ func (s *DB) GetIndexID(folder string, device protocol.DeviceID) (protocol.Index
 	return indexIDFromHex(indexID)
 }
 
-func (s *DB) SetIndexID(folder string, device protocol.DeviceID, id protocol.IndexID) error {
+func (s *folderDB) SetIndexID(device protocol.DeviceID, id protocol.IndexID) error {
 	s.updateLock.Lock()
 	defer s.updateLock.Unlock()
 
-	folderIdx, err := s.folderIdxLocked(folder)
-	if err != nil {
-		return wrap(err, "folder idx")
-	}
 	deviceIdx, err := s.deviceIdxLocked(device)
 	if err != nil {
 		return wrap(err, "device idx")
 	}
 
 	if _, err := s.stmt(`
-		INSERT OR REPLACE INTO indexids (folder_idx, device_idx, index_id, sequence) values (?, ?, ?, 0)
-	`).Exec(folderIdx, deviceIdx, indexIDToHex(id)); err != nil {
+		INSERT OR REPLACE INTO indexids (device_idx, index_id, sequence) values (?, ?, 0)
+	`).Exec(deviceIdx, indexIDToHex(id)); err != nil {
 		return wrap(err, "insert")
 	}
 	return nil
 }
 
-func (s *DB) DropAllIndexIDs() error {
+func (s *folderDB) DropAllIndexIDs() error {
 	s.updateLock.Lock()
 	defer s.updateLock.Unlock()
 	_, err := s.stmt(`DELETE FROM indexids`).Exec()
 	return wrap(err)
 }
 
-func (s *DB) GetDeviceSequence(folder string, device protocol.DeviceID) (int64, error) {
+func (s *folderDB) GetDeviceSequence(device protocol.DeviceID) (int64, error) {
 	var res sql.NullInt64
 	err := s.stmt(`
 		SELECT sequence FROM indexids i
-		INNER JOIN folders o ON o.idx = i.folder_idx
 		INNER JOIN devices d ON d.idx = i.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ?
-	`).Get(&res, folder, device.String())
+		WHERE d.device_id = ?
+	`).Get(&res, device.String())
 	if errors.Is(err, sql.ErrNoRows) {
 		return 0, nil
 	}
@@ -118,7 +107,7 @@ func (s *DB) GetDeviceSequence(folder string, device protocol.DeviceID) (int64,
 	return res.Int64, nil
 }
 
-func (s *DB) RemoteSequences(folder string) (map[protocol.DeviceID]int64, error) {
+func (s *folderDB) RemoteSequences() (map[protocol.DeviceID]int64, error) {
 	type row struct {
 		Device string
 		Seq    int64
@@ -126,10 +115,9 @@ func (s *DB) RemoteSequences(folder string) (map[protocol.DeviceID]int64, error)
 
 	it, errFn := iterStructs[row](s.stmt(`
 		SELECT d.device_id AS device, i.sequence AS seq FROM indexids i
-		INNER JOIN folders o ON o.idx = i.folder_idx
 		INNER JOIN devices d ON d.idx = i.device_idx
-		WHERE o.folder_id = ? AND i.device_idx != {{.LocalDeviceIdx}}
-	`).Queryx(folder))
+		WHERE i.device_idx != {{.LocalDeviceIdx}}
+	`).Queryx())
 
 	res := make(map[protocol.DeviceID]int64)
 	for row, err := range itererr.Zip(it, errFn) {

internal/db/sqlite/db_local.go → internal/db/sqlite/folderdb_local.go

@@ -18,7 +18,7 @@ import (
 	"github.com/syncthing/syncthing/lib/protocol"
 )
 
-func (s *DB) GetDeviceFile(folder string, device protocol.DeviceID, file string) (protocol.FileInfo, bool, error) {
+func (s *folderDB) GetDeviceFile(device protocol.DeviceID, file string) (protocol.FileInfo, bool, error) {
 	file = osutil.NormalizedFilename(file)
 
 	var ind indirectFI
@@ -27,9 +27,8 @@ func (s *DB) GetDeviceFile(folder string, device protocol.DeviceID, file string)
 		INNER JOIN files f on fi.sequence = f.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = f.blocklist_hash
 		INNER JOIN devices d ON f.device_idx = d.idx
-		INNER JOIN folders o ON f.folder_idx = o.idx
-		WHERE o.folder_id = ? AND d.device_id = ? AND f.name = ?
-	`).Get(&ind, folder, device.String(), file)
+		WHERE d.device_id = ? AND f.name = ?
+	`).Get(&ind, device.String(), file)
 	if errors.Is(err, sql.ErrNoRows) {
 		return protocol.FileInfo{}, false, nil
 	}
@@ -43,19 +42,18 @@ func (s *DB) GetDeviceFile(folder string, device protocol.DeviceID, file string)
 	return fi, true, nil
 }
 
-func (s *DB) AllLocalFiles(folder string, device protocol.DeviceID) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) AllLocalFiles(device protocol.DeviceID) (iter.Seq[protocol.FileInfo], func() error) {
 	it, errFn := iterStructs[indirectFI](s.stmt(`
 		SELECT fi.fiprotobuf, bl.blprotobuf FROM fileinfos fi
 		INNER JOIN files f on fi.sequence = f.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = f.blocklist_hash
-		INNER JOIN folders o ON o.idx = f.folder_idx
 		INNER JOIN devices d ON d.idx = f.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ?
-	`).Queryx(folder, device.String()))
+		WHERE d.device_id = ?
+	`).Queryx(device.String()))
 	return itererr.Map(it, errFn, indirectFI.FileInfo)
 }
 
-func (s *DB) AllLocalFilesBySequence(folder string, device protocol.DeviceID, startSeq int64, limit int) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) AllLocalFilesBySequence(device protocol.DeviceID, startSeq int64, limit int) (iter.Seq[protocol.FileInfo], func() error) {
 	var limitStr string
 	if limit > 0 {
 		limitStr = fmt.Sprintf(" LIMIT %d", limit)
@@ -64,17 +62,16 @@ func (s *DB) AllLocalFilesBySequence(folder string, device protocol.DeviceID, st
 		SELECT fi.fiprotobuf, bl.blprotobuf FROM fileinfos fi
 		INNER JOIN files f on fi.sequence = f.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = f.blocklist_hash
-		INNER JOIN folders o ON o.idx = f.folder_idx
 		INNER JOIN devices d ON d.idx = f.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ? AND f.sequence >= ?
+		WHERE d.device_id = ? AND f.sequence >= ?
 		ORDER BY f.sequence`+limitStr).Queryx(
-		folder, device.String(), startSeq))
+		device.String(), startSeq))
 	return itererr.Map(it, errFn, indirectFI.FileInfo)
 }
 
-func (s *DB) AllLocalFilesWithPrefix(folder string, device protocol.DeviceID, prefix string) (iter.Seq[protocol.FileInfo], func() error) {
+func (s *folderDB) AllLocalFilesWithPrefix(device protocol.DeviceID, prefix string) (iter.Seq[protocol.FileInfo], func() error) {
 	if prefix == "" {
-		return s.AllLocalFiles(folder, device)
+		return s.AllLocalFiles(device)
 	}
 
 	prefix = osutil.NormalizedFilename(prefix)
@@ -84,37 +81,20 @@ func (s *DB) AllLocalFilesWithPrefix(folder string, device protocol.DeviceID, pr
 		SELECT fi.fiprotobuf, bl.blprotobuf FROM fileinfos fi
 		INNER JOIN files f on fi.sequence = f.sequence
 		LEFT JOIN blocklists bl ON bl.blocklist_hash = f.blocklist_hash
-		INNER JOIN folders o ON o.idx = f.folder_idx
 		INNER JOIN devices d ON d.idx = f.device_idx
-		WHERE o.folder_id = ? AND d.device_id = ? AND f.name >= ? AND f.name < ?
-	`, folder, device.String(), prefix, end))
+		WHERE d.device_id = ? AND f.name >= ? AND f.name < ?
+	`, device.String(), prefix, end))
 	return itererr.Map(it, errFn, indirectFI.FileInfo)
 }
 
-func (s *DB) AllLocalFilesWithBlocksHash(folder string, h []byte) (iter.Seq[db.FileMetadata], func() error) {
+func (s *folderDB) AllLocalFilesWithBlocksHash(h []byte) (iter.Seq[db.FileMetadata], func() error) {
 	return iterStructs[db.FileMetadata](s.stmt(`
 		SELECT f.sequence, f.name, f.type, f.modified as modnanos, f.size, f.deleted, f.invalid, f.local_flags as localflags FROM files f
-		INNER JOIN folders o ON o.idx = f.folder_idx
-		WHERE o.folder_id = ? AND f.device_idx = {{.LocalDeviceIdx}} AND f.blocklist_hash = ?
-	`).Queryx(folder, h))
-}
-
-func (s *DB) AllLocalFilesWithBlocksHashAnyFolder(h []byte) (iter.Seq2[string, db.FileMetadata], func() error) {
-	type row struct {
-		FolderID string `db:"folder_id"`
-		db.FileMetadata
-	}
-	it, errFn := iterStructs[row](s.stmt(`
-		SELECT o.folder_id, f.sequence, f.name, f.type, f.modified as modnanos, f.size, f.deleted, f.invalid, f.local_flags as localflags FROM files f
-		INNER JOIN folders o ON o.idx = f.folder_idx
 		WHERE f.device_idx = {{.LocalDeviceIdx}} AND f.blocklist_hash = ?
 	`).Queryx(h))
-	return itererr.Map2(it, errFn, func(r row) (string, db.FileMetadata, error) {
-		return r.FolderID, r.FileMetadata, nil
-	})
 }
 
-func (s *DB) AllLocalBlocksWithHash(hash []byte) (iter.Seq[db.BlockMapEntry], func() error) {
+func (s *folderDB) AllLocalBlocksWithHash(hash []byte) (iter.Seq[db.BlockMapEntry], func() error) {
 	// We involve the files table in this select because deletion of blocks
 	// & blocklists is deferred (garbage collected) while the files list is
 	// not. This filters out blocks that are in fact deleted.
@@ -124,3 +104,25 @@ func (s *DB) AllLocalBlocksWithHash(hash []byte) (iter.Seq[db.BlockMapEntry], fu
 		WHERE f.device_idx = {{.LocalDeviceIdx}} AND b.hash = ?
 	`).Queryx(hash))
 }
+
+func (s *folderDB) ListDevicesForFolder() ([]protocol.DeviceID, error) {
+	var res []string
+	err := s.stmt(`
+		SELECT DISTINCT d.device_id FROM counts s
+		INNER JOIN devices d ON d.idx = s.device_idx
+		WHERE s.count > 0 AND s.device_idx != {{.LocalDeviceIdx}}
+		ORDER BY d.device_id
+	`).Select(&res)
+	if err != nil {
+		return nil, wrap(err)
+	}
+
+	devs := make([]protocol.DeviceID, len(res))
+	for i, s := range res {
+		devs[i], err = protocol.DeviceIDFromString(s)
+		if err != nil {
+			return nil, wrap(err)
+		}
+	}
+	return devs, nil
+}

internal/db/sqlite/folderdb_mtimes.go

@@ -0,0 +1,45 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"time"
+)
+
+func (s *folderDB) GetMtime(name string) (ondisk, virtual time.Time) {
+	var res struct {
+		Ondisk  int64
+		Virtual int64
+	}
+	if err := s.stmt(`
+		SELECT m.ondisk, m.virtual FROM mtimes m
+		WHERE m.name = ?
+	`).Get(&res, name); err != nil {
+		return time.Time{}, time.Time{}
+	}
+	return time.Unix(0, res.Ondisk), time.Unix(0, res.Virtual)
+}
+
+func (s *folderDB) PutMtime(name string, ondisk, virtual time.Time) error {
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+	_, err := s.stmt(`
+		INSERT OR REPLACE INTO mtimes (name, ondisk, virtual)
+		VALUES (?, ?, ?)
+	`).Exec(name, ondisk.UnixNano(), virtual.UnixNano())
+	return wrap(err)
+}
+
+func (s *folderDB) DeleteMtime(name string) error {
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+	_, err := s.stmt(`
+		DELETE FROM mtimes
+		WHERE name = ?
+	`).Exec(name)
+	return wrap(err)
+}

internal/db/sqlite/folderdb_open.go

@@ -0,0 +1,110 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"time"
+
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+type folderDB struct {
+	folderID string
+	*baseDB
+
+	localDeviceIdx  int64
+	deleteRetention time.Duration
+}
+
+func openFolderDB(folder, path string, deleteRetention time.Duration) (*folderDB, error) {
+	pragmas := []string{
+		"journal_mode = WAL",
+		"optimize = 0x10002",
+		"auto_vacuum = INCREMENTAL",
+		"default_temp_store = MEMORY",
+		"temp_store = MEMORY",
+	}
+	schemas := []string{
+		"sql/schema/common/*",
+		"sql/schema/folder/*",
+	}
+
+	base, err := openBase(path, maxDBConns, pragmas, schemas, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	fdb := &folderDB{
+		folderID:        folder,
+		baseDB:          base,
+		deleteRetention: deleteRetention,
+	}
+
+	_ = fdb.PutKV("folderID", []byte(folder))
+
+	// Touch device IDs that should always exist and have a low index
+	// numbers, and will never change
+	fdb.localDeviceIdx, _ = fdb.deviceIdxLocked(protocol.LocalDeviceID)
+	fdb.tplInput["LocalDeviceIdx"] = fdb.localDeviceIdx
+
+	return fdb, nil
+}
+
+// Open the database with options suitable for the migration inserts. This
+// is not a safe mode of operation for normal processing, use only for bulk
+// inserts with a close afterwards.
+func openFolderDBForMigration(folder, path string, deleteRetention time.Duration) (*folderDB, error) {
+	pragmas := []string{
+		"journal_mode = OFF",
+		"default_temp_store = MEMORY",
+		"temp_store = MEMORY",
+		"foreign_keys = 0",
+		"synchronous = 0",
+		"locking_mode = EXCLUSIVE",
+	}
+	schemas := []string{
+		"sql/schema/common/*",
+		"sql/schema/folder/*",
+	}
+
+	base, err := openBase(path, 1, pragmas, schemas, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	fdb := &folderDB{
+		folderID:        folder,
+		baseDB:          base,
+		deleteRetention: deleteRetention,
+	}
+
+	// Touch device IDs that should always exist and have a low index
+	// numbers, and will never change
+	fdb.localDeviceIdx, _ = fdb.deviceIdxLocked(protocol.LocalDeviceID)
+	fdb.tplInput["LocalDeviceIdx"] = fdb.localDeviceIdx
+
+	return fdb, nil
+}
+
+func (s *folderDB) deviceIdxLocked(deviceID protocol.DeviceID) (int64, error) {
+	devStr := deviceID.String()
+	if _, err := s.stmt(`
+		INSERT OR IGNORE INTO devices(device_id)
+		VALUES (?)
+	`).Exec(devStr); err != nil {
+		return 0, wrap(err)
+	}
+	var idx int64
+	if err := s.stmt(`
+		SELECT idx FROM devices
+		WHERE device_id = ?
+	`).Get(&idx, devStr); err != nil {
+		return 0, wrap(err)
+	}
+
+	return idx, nil
+}

internal/db/sqlite/folderdb_update.go

@@ -0,0 +1,531 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"cmp"
+	"context"
+	"fmt"
+	"slices"
+
+	"github.com/jmoiron/sqlx"
+	"github.com/syncthing/syncthing/internal/gen/dbproto"
+	"github.com/syncthing/syncthing/internal/itererr"
+	"github.com/syncthing/syncthing/lib/osutil"
+	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/sliceutil"
+	"google.golang.org/protobuf/proto"
+)
+
+const (
+	// Arbitrarily chosen values for checkpoint frequency....
+	updatePointsPerFile   = 100
+	updatePointsPerBlock  = 1
+	updatePointsThreshold = 250_000
+)
+
+func (s *folderDB) Update(device protocol.DeviceID, fs []protocol.FileInfo) error {
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+
+	deviceIdx, err := s.deviceIdxLocked(device)
+	if err != nil {
+		return wrap(err)
+	}
+
+	tx, err := s.sql.BeginTxx(context.Background(), nil)
+	if err != nil {
+		return wrap(err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+	txp := &txPreparedStmts{Tx: tx}
+
+	//nolint:sqlclosecheck
+	insertFileStmt, err := txp.Preparex(`
+		INSERT OR REPLACE INTO files (device_idx, remote_sequence, name, type, modified, size, version, deleted, invalid, local_flags, blocklist_hash)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		RETURNING sequence
+	`)
+	if err != nil {
+		return wrap(err, "prepare insert file")
+	}
+
+	//nolint:sqlclosecheck
+	insertFileInfoStmt, err := txp.Preparex(`
+		INSERT INTO fileinfos (sequence, fiprotobuf)
+		VALUES (?, ?)
+	`)
+	if err != nil {
+		return wrap(err, "prepare insert fileinfo")
+	}
+
+	//nolint:sqlclosecheck
+	insertBlockListStmt, err := txp.Preparex(`
+		INSERT OR IGNORE INTO blocklists (blocklist_hash, blprotobuf)
+		VALUES (?, ?)
+	`)
+	if err != nil {
+		return wrap(err, "prepare insert blocklist")
+	}
+
+	var prevRemoteSeq int64
+	for i, f := range fs {
+		f.Name = osutil.NormalizedFilename(f.Name)
+
+		var blockshash *[]byte
+		if len(f.Blocks) > 0 {
+			f.BlocksHash = protocol.BlocksHash(f.Blocks)
+			blockshash = &f.BlocksHash
+		} else {
+			f.BlocksHash = nil
+		}
+
+		if f.Type == protocol.FileInfoTypeDirectory {
+			f.Size = 128 // synthetic directory size
+		}
+
+		// Insert the file.
+		//
+		// If it is a remote file, set remote_sequence otherwise leave it at
+		// null. Returns the new local sequence.
+		var remoteSeq *int64
+		if device != protocol.LocalDeviceID {
+			if i > 0 && f.Sequence == prevRemoteSeq {
+				return fmt.Errorf("duplicate remote sequence number %d", prevRemoteSeq)
+			}
+			prevRemoteSeq = f.Sequence
+			remoteSeq = &f.Sequence
+		}
+		var localSeq int64
+		if err := insertFileStmt.Get(&localSeq, deviceIdx, remoteSeq, f.Name, f.Type, f.ModTime().UnixNano(), f.Size, f.Version.String(), f.IsDeleted(), f.IsInvalid(), f.LocalFlags, blockshash); err != nil {
+			return wrap(err, "insert file")
+		}
+
+		if len(f.Blocks) > 0 {
+			// Indirect the block list
+			blocks := sliceutil.Map(f.Blocks, protocol.BlockInfo.ToWire)
+			bs, err := proto.Marshal(&dbproto.BlockList{Blocks: blocks})
+			if err != nil {
+				return wrap(err, "marshal blocklist")
+			}
+			if _, err := insertBlockListStmt.Exec(f.BlocksHash, bs); err != nil {
+				return wrap(err, "insert blocklist")
+			}
+
+			if device == protocol.LocalDeviceID {
+				// Insert all blocks
+				if err := s.insertBlocksLocked(txp, f.BlocksHash, f.Blocks); err != nil {
+					return wrap(err, "insert blocks")
+				}
+			}
+
+			f.Blocks = nil
+		}
+
+		// Insert the fileinfo
+		if device == protocol.LocalDeviceID {
+			f.Sequence = localSeq
+		}
+		bs, err := proto.Marshal(f.ToWire(true))
+		if err != nil {
+			return wrap(err, "marshal fileinfo")
+		}
+		if _, err := insertFileInfoStmt.Exec(localSeq, bs); err != nil {
+			return wrap(err, "insert fileinfo")
+		}
+
+		// Update global and need
+		if err := s.recalcGlobalForFile(txp, f.Name); err != nil {
+			return wrap(err)
+		}
+	}
+
+	if err := tx.Commit(); err != nil {
+		return wrap(err)
+	}
+
+	s.periodicCheckpointLocked(fs)
+	return nil
+}
+
+func (s *folderDB) DropDevice(device protocol.DeviceID) error {
+	if device == protocol.LocalDeviceID {
+		panic("bug: cannot drop local device")
+	}
+
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+
+	tx, err := s.sql.BeginTxx(context.Background(), nil)
+	if err != nil {
+		return wrap(err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+	txp := &txPreparedStmts{Tx: tx}
+
+	// Drop the device, which cascades to delete all files etc for it
+	if _, err := tx.Exec(`DELETE FROM devices WHERE device_id = ?`, device.String()); err != nil {
+		return wrap(err)
+	}
+
+	// Recalc the globals for all affected folders
+	if err := s.recalcGlobalForFolder(txp); err != nil {
+		return wrap(err)
+	}
+
+	return wrap(tx.Commit())
+}
+
+func (s *folderDB) DropAllFiles(device protocol.DeviceID) error {
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+
+	// This is a two part operation, first dropping all the files and then
+	// recalculating the global state for the entire folder.
+
+	deviceIdx, err := s.deviceIdxLocked(device)
+	if err != nil {
+		return wrap(err)
+	}
+
+	tx, err := s.sql.BeginTxx(context.Background(), nil)
+	if err != nil {
+		return wrap(err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+	txp := &txPreparedStmts{Tx: tx}
+
+	// Drop all the file entries
+
+	result, err := tx.Exec(`
+		DELETE FROM files
+		WHERE device_idx = ?
+	`, deviceIdx)
+	if err != nil {
+		return wrap(err)
+	}
+	if n, err := result.RowsAffected(); err == nil && n == 0 {
+		// The delete affected no rows, so we don't need to redo the entire
+		// global/need calculation.
+		return wrap(tx.Commit())
+	}
+
+	// Recalc global for the entire folder
+
+	if err := s.recalcGlobalForFolder(txp); err != nil {
+		return wrap(err)
+	}
+	return wrap(tx.Commit())
+}
+
+func (s *folderDB) DropFilesNamed(device protocol.DeviceID, names []string) error {
+	for i := range names {
+		names[i] = osutil.NormalizedFilename(names[i])
+	}
+
+	s.updateLock.Lock()
+	defer s.updateLock.Unlock()
+
+	deviceIdx, err := s.deviceIdxLocked(device)
+	if err != nil {
+		return wrap(err)
+	}
+
+	tx, err := s.sql.BeginTxx(context.Background(), nil)
+	if err != nil {
+		return wrap(err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+	txp := &txPreparedStmts{Tx: tx}
+
+	// Drop the named files
+
+	query, args, err := sqlx.In(`
+		DELETE FROM files
+		WHERE device_idx = ? AND name IN (?)
+	`, deviceIdx, names)
+	if err != nil {
+		return wrap(err)
+	}
+	if _, err := tx.Exec(query, args...); err != nil {
+		return wrap(err)
+	}
+
+	// Recalc globals for the named files
+
+	for _, name := range names {
+		if err := s.recalcGlobalForFile(txp, name); err != nil {
+			return wrap(err)
+		}
+	}
+
+	return wrap(tx.Commit())
+}
+
+func (*folderDB) insertBlocksLocked(tx *txPreparedStmts, blocklistHash []byte, blocks []protocol.BlockInfo) error {
+	if len(blocks) == 0 {
+		return nil
+	}
+	bs := make([]map[string]any, len(blocks))
+	for i, b := range blocks {
+		bs[i] = map[string]any{
+			"hash":           b.Hash,
+			"blocklist_hash": blocklistHash,
+			"idx":            i,
+			"offset":         b.Offset,
+			"size":           b.Size,
+		}
+	}
+
+	// Very large block lists (>8000 blocks) result in "too many variables"
+	// error. Chunk it to a reasonable size.
+	for chunk := range slices.Chunk(bs, 1000) {
+		if _, err := tx.NamedExec(`
+			INSERT OR IGNORE INTO blocks (hash, blocklist_hash, idx, offset, size)
+			VALUES (:hash, :blocklist_hash, :idx, :offset, :size)
+		`, chunk); err != nil {
+			return wrap(err)
+		}
+	}
+	return nil
+}
+
+func (s *folderDB) recalcGlobalForFolder(txp *txPreparedStmts) error {
+	// Select files where there is no global, those are the ones we need to
+	// recalculate.
+	//nolint:sqlclosecheck
+	namesStmt, err := txp.Preparex(`
+		SELECT f.name FROM files f
+		WHERE NOT EXISTS (
+			SELECT 1 FROM files g
+			WHERE g.name = f.name AND g.local_flags & ? != 0
+		)
+		GROUP BY name
+	`)
+	if err != nil {
+		return wrap(err)
+	}
+	rows, err := namesStmt.Queryx(protocol.FlagLocalGlobal)
+	if err != nil {
+		return wrap(err)
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			return wrap(err)
+		}
+		if err := s.recalcGlobalForFile(txp, name); err != nil {
+			return wrap(err)
+		}
+	}
+	return wrap(rows.Err())
+}
+
+func (s *folderDB) recalcGlobalForFile(txp *txPreparedStmts, file string) error {
+	//nolint:sqlclosecheck
+	selStmt, err := txp.Preparex(`
+		SELECT name, device_idx, sequence, modified, version, deleted, invalid, local_flags FROM files
+		WHERE name = ?
+	`)
+	if err != nil {
+		return wrap(err)
+	}
+	es, err := itererr.Collect(iterStructs[fileRow](selStmt.Queryx(file)))
+	if err != nil {
+		return wrap(err)
+	}
+	if len(es) == 0 {
+		// shouldn't happen
+		return nil
+	}
+
+	// Sort the entries; the global entry is at the head of the list
+	slices.SortFunc(es, fileRow.Compare)
+
+	// The global version is the first one in the list that is not invalid,
+	// or just the first one in the list if all are invalid.
+	var global fileRow
+	globIdx := slices.IndexFunc(es, func(e fileRow) bool { return !e.Invalid })
+	if globIdx < 0 {
+		globIdx = 0
+	}
+	global = es[globIdx]
+
+	// We "have" the file if the position in the list of versions is at the
+	// global version or better, or if the version is the same as the global
+	// file (we might be further down the list due to invalid flags), or if
+	// the global is deleted and we don't have it at all...
+	localIdx := slices.IndexFunc(es, func(e fileRow) bool { return e.DeviceIdx == s.localDeviceIdx })
+	hasLocal := localIdx >= 0 && localIdx <= globIdx || // have a better or equal version
+		localIdx >= 0 && es[localIdx].Version.Equal(global.Version.Vector) || // have an equal version but invalid/ignored
+		localIdx < 0 && global.Deleted // missing it, but the global is also deleted
+
+	// Set the global flag on the global entry. Set the need flag if the
+	// local device needs this file, unless it's invalid.
+	global.LocalFlags |= protocol.FlagLocalGlobal
+	if hasLocal || global.Invalid {
+		global.LocalFlags &= ^protocol.FlagLocalNeeded
+	} else {
+		global.LocalFlags |= protocol.FlagLocalNeeded
+	}
+	//nolint:sqlclosecheck
+	upStmt, err := txp.Prepare(`
+		UPDATE files SET local_flags = ?
+		WHERE device_idx = ? AND sequence = ?
+	`)
+	if err != nil {
+		return wrap(err)
+	}
+	if _, err := upStmt.Exec(global.LocalFlags, global.DeviceIdx, global.Sequence); err != nil {
+		return wrap(err)
+	}
+
+	// Clear the need and global flags on all other entries
+	//nolint:sqlclosecheck
+	upStmt, err = txp.Prepare(`
+		UPDATE files SET local_flags = local_flags & ?
+		WHERE name = ? AND sequence != ? AND local_flags & ? != 0
+	`)
+	if err != nil {
+		return wrap(err)
+	}
+	if _, err := upStmt.Exec(^(protocol.FlagLocalNeeded | protocol.FlagLocalGlobal), global.Name, global.Sequence, protocol.FlagLocalNeeded|protocol.FlagLocalGlobal); err != nil {
+		return wrap(err)
+	}
+
+	return nil
+}
+
+func (s *DB) folderIdxLocked(folderID string) (int64, error) {
+	if _, err := s.stmt(`
+		INSERT OR IGNORE INTO folders(folder_id)
+		VALUES (?)
+	`).Exec(folderID); err != nil {
+		return 0, wrap(err)
+	}
+	var idx int64
+	if err := s.stmt(`
+		SELECT idx FROM folders
+		WHERE folder_id = ?
+	`).Get(&idx, folderID); err != nil {
+		return 0, wrap(err)
+	}
+
+	return idx, nil
+}
+
+type fileRow struct {
+	Name       string
+	Version    dbVector
+	DeviceIdx  int64 `db:"device_idx"`
+	Sequence   int64
+	Modified   int64
+	Size       int64
+	LocalFlags int64 `db:"local_flags"`
+	Deleted    bool
+	Invalid    bool
+}
+
+func (e fileRow) Compare(other fileRow) int {
+	// From FileInfo.WinsConflict
+	vc := e.Version.Vector.Compare(other.Version.Vector)
+	switch vc {
+	case protocol.Equal:
+		if e.Invalid != other.Invalid {
+			if e.Invalid {
+				return 1
+			}
+			return -1
+		}
+
+		// Compare the device ID index, lower is better. This is only
+		// deterministic to the extent that LocalDeviceID will always be the
+		// lowest one, order between remote devices is random (and
+		// irrelevant).
+		return cmp.Compare(e.DeviceIdx, other.DeviceIdx)
+	case protocol.Greater: // we are newer
+		return -1
+	case protocol.Lesser: // we are older
+		return 1
+	case protocol.ConcurrentGreater, protocol.ConcurrentLesser: // there is a conflict
+		if e.Invalid != other.Invalid {
+			if e.Invalid { // we are invalid, we lose
+				return 1
+			}
+			return -1 // they are invalid, we win
+		}
+		if e.Deleted != other.Deleted {
+			if e.Deleted { // we are deleted, we lose
+				return 1
+			}
+			return -1 // they are deleted, we win
+		}
+		if d := cmp.Compare(e.Modified, other.Modified); d != 0 {
+			return -d // positive d means we were newer, so we win (negative return)
+		}
+		if vc == protocol.ConcurrentGreater {
+			return -1 // we have a better device ID, we win
+		}
+		return 1 // they win
+	default:
+		return 0
+	}
+}
+
+func (s *folderDB) periodicCheckpointLocked(fs []protocol.FileInfo) {
+	// Induce periodic checkpoints. We add points for each file and block,
+	// and checkpoint when we've written more than a threshold of points.
+	// This ensures we do not go too long without a checkpoint, while also
+	// not doing it incessantly for every update.
+	s.updatePoints += updatePointsPerFile * len(fs)
+	for _, f := range fs {
+		s.updatePoints += len(f.Blocks) * updatePointsPerBlock
+	}
+	if s.updatePoints > updatePointsThreshold {
+		conn, err := s.sql.Conn(context.Background())
+		if err != nil {
+			l.Debugln(s.baseName, "conn:", err)
+			return
+		}
+		defer conn.Close()
+		if _, err := conn.ExecContext(context.Background(), `PRAGMA journal_size_limit = 8388608`); err != nil {
+			l.Debugln(s.baseName, "PRAGMA journal_size_limit:", err)
+		}
+
+		// Every 50th checkpoint becomes a truncate, in an effort to bring
+		// down the size now and then.
+		checkpointType := "RESTART"
+		if s.checkpointsCount > 50 {
+			checkpointType = "TRUNCATE"
+		}
+		cmd := fmt.Sprintf(`PRAGMA wal_checkpoint(%s)`, checkpointType)
+		row := conn.QueryRowContext(context.Background(), cmd)
+
+		var res, modified, moved int
+		if row.Err() != nil {
+			l.Debugln(s.baseName, cmd+":", err)
+		} else if err := row.Scan(&res, &modified, &moved); err != nil {
+			l.Debugln(s.baseName, cmd+" (scan):", err)
+		} else {
+			l.Debugln(s.baseName, cmd, s.checkpointsCount, "at", s.updatePoints, "returned", res, modified, moved)
+		}
+
+		// Reset the truncate counter when a truncate succeeded. If it
+		// failed, we'll keep trying it until we succeed. Increase it faster
+		// when we fail to checkpoint, as it's more likely the WAL is
+		// growing and will need truncation when we get out of this state.
+		if res == 1 {
+			s.checkpointsCount += 10
+		} else if res == 0 && checkpointType == "TRUNCATE" {
+			s.checkpointsCount = 0
+		} else {
+			s.checkpointsCount++
+		}
+		s.updatePoints = 0
+	}
+}

internal/db/sqlite/sql/schema/00-indexes.sql → internal/db/sqlite/sql/schema/folder/00-indexes.sql

@@ -4,16 +4,9 @@
 -- License, v. 2.0. If a copy of the MPL was not distributed with this file,
 -- You can obtain one at https://mozilla.org/MPL/2.0/.
 
--- folders map folder IDs as used by Syncthing to database folder indexes
-CREATE TABLE IF NOT EXISTS folders (
-    idx INTEGER NOT NULL PRIMARY KEY,
-    folder_id TEXT NOT NULL UNIQUE COLLATE BINARY
-) STRICT
-;
-
 -- devices map device IDs as used by Syncthing to database device indexes
 CREATE TABLE IF NOT EXISTS devices (
-    idx INTEGER NOT NULL PRIMARY KEY,
+    idx INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
     device_id TEXT NOT NULL UNIQUE COLLATE BINARY
 ) STRICT
 ;

internal/db/sqlite/sql/schema/20-files.sql → internal/db/sqlite/sql/schema/folder/20-files.sql

@@ -22,7 +22,6 @@
 -- Need bit. This allows for very efficient lookup of files needing handling
 -- on this device, which is a common query.
 CREATE TABLE IF NOT EXISTS files (
-    folder_idx INTEGER NOT NULL,
     device_idx INTEGER NOT NULL, -- actual device ID or LocalDeviceID
     sequence INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, -- our local database sequence, for each and every entry
     remote_sequence INTEGER, -- remote device's sequence number, null for local or synthetic entries
@@ -35,8 +34,7 @@ CREATE TABLE IF NOT EXISTS files (
     invalid INTEGER NOT NULL, -- boolean
     local_flags INTEGER NOT NULL,
     blocklist_hash BLOB, -- null when there are no blocks
-    FOREIGN KEY(device_idx) REFERENCES devices(idx) ON DELETE CASCADE,
-    FOREIGN KEY(folder_idx) REFERENCES folders(idx) ON DELETE CASCADE
+    FOREIGN KEY(device_idx) REFERENCES devices(idx) ON DELETE CASCADE
 ) STRICT
 ;
 -- FileInfos store the actual protobuf object. We do this separately to keep
@@ -48,15 +46,15 @@ CREATE TABLE IF NOT EXISTS fileinfos (
 ) STRICT
 ;
 -- There can be only one file per folder, device, and remote sequence number
-CREATE UNIQUE INDEX IF NOT EXISTS files_remote_sequence ON files (folder_idx, device_idx, remote_sequence)
+CREATE UNIQUE INDEX IF NOT EXISTS files_remote_sequence ON files (device_idx, remote_sequence)
     WHERE remote_sequence IS NOT NULL
 ;
 -- There can be only one file per folder, device, and name
-CREATE UNIQUE INDEX IF NOT EXISTS files_device_name ON files (folder_idx, device_idx, name)
+CREATE UNIQUE INDEX IF NOT EXISTS files_device_name ON files (device_idx, name)
 ;
 -- We want to be able to look up & iterate files based on just folder and name
-CREATE INDEX IF NOT EXISTS files_name_only ON files (folder_idx, name)
+CREATE INDEX IF NOT EXISTS files_name_only ON files (name)
 ;
 -- We want to be able to look up & iterate files based on blocks hash
-CREATE INDEX IF NOT EXISTS files_blocklist_hash_only ON files (blocklist_hash, device_idx, folder_idx) WHERE blocklist_hash IS NOT NULL
+CREATE INDEX IF NOT EXISTS files_blocklist_hash_only ON files (blocklist_hash, device_idx) WHERE blocklist_hash IS NOT NULL
 ;

internal/db/sqlite/sql/schema/30-indexids.sql → internal/db/sqlite/sql/schema/folder/30-indexids.sql

@@ -7,18 +7,16 @@
 -- indexids holds the index ID and maximum sequence for a given device and folder
 CREATE TABLE IF NOT EXISTS indexids (
     device_idx INTEGER NOT NULL,
-    folder_idx INTEGER NOT NULL,
     index_id TEXT NOT NULL COLLATE BINARY,
     sequence INTEGER NOT NULL DEFAULT 0,
-    PRIMARY KEY(device_idx, folder_idx),
-    FOREIGN KEY(folder_idx) REFERENCES folders(idx) ON DELETE CASCADE,
+    PRIMARY KEY(device_idx),
     FOREIGN KEY(device_idx) REFERENCES devices(idx) ON DELETE CASCADE
 ) STRICT, WITHOUT ROWID
 ;
 CREATE TRIGGER IF NOT EXISTS indexids_seq AFTER INSERT ON files
 BEGIN
-    INSERT INTO indexids (folder_idx, device_idx, index_id, sequence)
-        VALUES (NEW.folder_idx, NEW.device_idx, "", COALESCE(NEW.remote_sequence, NEW.sequence))
+    INSERT INTO indexids (device_idx, index_id, sequence)
+        VALUES (NEW.device_idx, "", COALESCE(NEW.remote_sequence, NEW.sequence))
         ON CONFLICT DO UPDATE SET sequence = COALESCE(NEW.remote_sequence, NEW.sequence);
 END
 ;

internal/db/sqlite/sql/schema/40-counts.sql → internal/db/sqlite/sql/schema/folder/40-counts.sql

@@ -9,16 +9,14 @@
 -- Counts and sizes are maintained for each device, folder, type, flag bits
 -- combination.
 CREATE TABLE IF NOT EXISTS counts (
-    folder_idx INTEGER NOT NULL,
     device_idx INTEGER NOT NULL,
     type INTEGER NOT NULL,
     local_flags INTEGER NOT NULL,
     count INTEGER NOT NULL,
     size INTEGER NOT NULL,
     deleted INTEGER NOT NULL, -- boolean
-    PRIMARY KEY(folder_idx, device_idx, type, local_flags, deleted),
-    FOREIGN KEY(device_idx) REFERENCES devices(idx) ON DELETE CASCADE,
-    FOREIGN KEY(folder_idx) REFERENCES folders(idx) ON DELETE CASCADE
+    PRIMARY KEY(device_idx, type, local_flags, deleted),
+    FOREIGN KEY(device_idx) REFERENCES devices(idx) ON DELETE CASCADE
 ) STRICT, WITHOUT ROWID
 ;
 
@@ -26,28 +24,24 @@ CREATE TABLE IF NOT EXISTS counts (
 
 CREATE TRIGGER IF NOT EXISTS counts_insert AFTER INSERT ON files
 BEGIN
-    INSERT INTO counts (folder_idx, device_idx, type, local_flags, count, size, deleted)
-        VALUES (NEW.folder_idx, NEW.device_idx, NEW.type, NEW.local_flags, 1, NEW.size, NEW.deleted)
+    INSERT INTO counts (device_idx, type, local_flags, count, size, deleted)
+        VALUES (NEW.device_idx, NEW.type, NEW.local_flags, 1, NEW.size, NEW.deleted)
         ON CONFLICT DO UPDATE SET count = count + 1, size = size + NEW.size;
 END
 ;
 CREATE TRIGGER IF NOT EXISTS counts_delete AFTER DELETE ON files
 BEGIN
     UPDATE counts SET count = count - 1, size = size - OLD.size
-        WHERE folder_idx = OLD.folder_idx AND device_idx = OLD.device_idx AND type = OLD.type AND local_flags = OLD.local_flags AND deleted = OLD.deleted;
+        WHERE device_idx = OLD.device_idx AND type = OLD.type AND local_flags = OLD.local_flags AND deleted = OLD.deleted;
 END
 ;
 CREATE TRIGGER IF NOT EXISTS counts_update AFTER UPDATE OF local_flags ON files
 WHEN NEW.local_flags != OLD.local_flags
 BEGIN
-    INSERT INTO counts (folder_idx, device_idx, type, local_flags, count, size, deleted)
-        VALUES (NEW.folder_idx, NEW.device_idx, NEW.type, NEW.local_flags, 1, NEW.size, NEW.deleted)
+    INSERT INTO counts (device_idx, type, local_flags, count, size, deleted)
+        VALUES (NEW.device_idx, NEW.type, NEW.local_flags, 1, NEW.size, NEW.deleted)
         ON CONFLICT DO UPDATE SET count = count + 1, size = size + NEW.size;
     UPDATE counts SET count = count - 1, size = size - OLD.size
-        WHERE folder_idx = OLD.folder_idx AND device_idx = OLD.device_idx AND type = OLD.type AND local_flags = OLD.local_flags AND deleted = OLD.deleted;
+        WHERE device_idx = OLD.device_idx AND type = OLD.type AND local_flags = OLD.local_flags AND deleted = OLD.deleted;
 END
 ;
-DROP TRIGGER IF EXISTS counts_update_add -- tmp migration
-;
-DROP TRIGGER IF EXISTS counts_update_del -- tmp migration
-;

internal/db/sqlite/sql/schema/50-mtimes.sql → internal/db/sqlite/sql/schema/folder/50-mtimes.sql

@@ -6,11 +6,9 @@
 
 --- Backing for the MtimeFS
 CREATE TABLE IF NOT EXISTS mtimes (
-    folder_idx INTEGER NOT NULL,
     name TEXT NOT NULL,
     ondisk INTEGER NOT NULL, -- unix nanos
     virtual INTEGER NOT NULL, -- unix nanos
-    PRIMARY KEY(folder_idx, name),
-    FOREIGN KEY(folder_idx) REFERENCES folders(idx) ON DELETE CASCADE
+    PRIMARY KEY(name)
 ) STRICT, WITHOUT ROWID
 ;

internal/db/sqlite/sql/schema/main/00-indexes.sql

@@ -0,0 +1,12 @@
+-- Copyright (C) 2025 The Syncthing Authors.
+--
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this file,
+-- You can obtain one at https://mozilla.org/MPL/2.0/.
+
+-- folders map folder IDs as used by Syncthing to database folder indexes
+CREATE TABLE IF NOT EXISTS folders (
+    idx INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    folder_id TEXT NOT NULL UNIQUE COLLATE BINARY
+) STRICT
+;

lib/locations/locations.go

@@ -48,7 +48,7 @@ const (
 	UserHomeBaseDir BaseDirEnum = "userHome"
 
 	levelDBDir          = "index-v0.14.0.db"
-	databaseName        = "index-v2.db"
+	databaseName        = "index-v2"
 	configFileName      = "config.xml"
 	defaultStateDir     = ".local/state/syncthing"
 	oldDefaultConfigDir = ".config/syncthing"

lib/model/folder_sendrecv.go

@@ -315,23 +315,15 @@ func (f *sendReceiveFolder) processNeeded(dbUpdateChan chan<- dbUpdateJob, copyC
 	fileDeletions := map[string]protocol.FileInfo{}
 	buckets := map[string][]protocol.FileInfo{}
 
-	// Buffer the full list of needed files. This is somewhat wasteful and
-	// uses a lot of memory, but we need to keep the duration of the
-	// database read short and not do a bunch of file and data I/O inside
-	// the loop. If we forego the ability for users to repriorize the pull
-	// queue on the fly we could do this in batches, though that would also
-	// be a bit slower and less efficient in other ways.
-	files, err := itererr.Collect(f.model.sdb.AllNeededGlobalFiles(f.folderID, protocol.LocalDeviceID, f.Order, 0, 0))
-	if err != nil {
-		return changed, nil, nil, err
-	}
-
 	// Iterate the list of items that we need and sort them into piles.
 	// Regular files to pull goes into the file queue, everything else
 	// (directories, symlinks and deletes) goes into the "process directly"
 	// pile.
 loop:
-	for _, file := range files {
+	for file, err := range itererr.Zip(f.model.sdb.AllNeededGlobalFiles(f.folderID, protocol.LocalDeviceID, f.Order, 0, 0)) {
+		if err != nil {
+			return changed, nil, nil, err
+		}
 		select {
 		case <-f.ctx.Done():
 			break loop
@@ -1353,58 +1345,58 @@ func (f *sendReceiveFolder) copierRoutine(in <-chan copyBlocksState, pullChan ch
 			buf = protocol.BufferPool.Upgrade(buf, int(block.Size))
 
 			found := false
-			for e, err := range itererr.Zip(f.model.sdb.AllLocalBlocksWithHash(block.Hash)) {
+			blocks, _ := f.model.sdb.AllLocalBlocksWithHash(block.Hash)
+			for _, e := range blocks {
+				res, err := f.model.sdb.AllLocalFilesWithBlocksHashAnyFolder(e.BlocklistHash)
 				if err != nil {
-					break
+					continue
 				}
-				it, errFn := f.model.sdb.AllLocalFilesWithBlocksHashAnyFolder(e.BlocklistHash)
-				for folderID, fi := range it {
+				for folderID, files := range res {
 					ffs := folderFilesystems[folderID]
-					fd, err := ffs.Open(fi.Name)
-					if err != nil {
-						continue
-					}
-					defer fd.Close()
-
-					_, err = fd.ReadAt(buf, e.Offset)
-					if err != nil {
-						fd.Close()
-						continue
-					}
+					for _, fi := range files {
+						fd, err := ffs.Open(fi.Name)
+						if err != nil {
+							continue
+						}
+						defer fd.Close()
 
-					// Hash is not SHA256 as it's an encrypted hash token. In that
-					// case we can't verify the block integrity so we'll take it on
-					// trust. (The other side can and will verify.)
-					if f.Type != config.FolderTypeReceiveEncrypted {
-						if err := f.verifyBuffer(buf, block); err != nil {
-							l.Debugln("Finder failed to verify buffer", err)
+						_, err = fd.ReadAt(buf, e.Offset)
+						if err != nil {
+							fd.Close()
 							continue
 						}
-					}
 
-					if f.CopyRangeMethod != config.CopyRangeMethodStandard {
-						err = f.withLimiter(func() error {
-							dstFd.mut.Lock()
-							defer dstFd.mut.Unlock()
-							return fs.CopyRange(f.CopyRangeMethod.ToFS(), fd, dstFd.fd, e.Offset, block.Offset, int64(block.Size))
-						})
-					} else {
-						err = f.limitedWriteAt(dstFd, buf, block.Offset)
-					}
-					if err != nil {
-						state.fail(fmt.Errorf("dst write: %w", err))
+						// Hash is not SHA256 as it's an encrypted hash token. In that
+						// case we can't verify the block integrity so we'll take it on
+						// trust. (The other side can and will verify.)
+						if f.Type != config.FolderTypeReceiveEncrypted {
+							if err := f.verifyBuffer(buf, block); err != nil {
+								l.Debugln("Finder failed to verify buffer", err)
+								continue
+							}
+						}
+
+						if f.CopyRangeMethod != config.CopyRangeMethodStandard {
+							err = f.withLimiter(func() error {
+								dstFd.mut.Lock()
+								defer dstFd.mut.Unlock()
+								return fs.CopyRange(f.CopyRangeMethod.ToFS(), fd, dstFd.fd, e.Offset, block.Offset, int64(block.Size))
+							})
+						} else {
+							err = f.limitedWriteAt(dstFd, buf, block.Offset)
+						}
+						if err != nil {
+							state.fail(fmt.Errorf("dst write: %w", err))
+							break
+						}
+						if fi.Name == state.file.Name {
+							state.copiedFromOrigin(block.Size)
+						} else {
+							state.copiedFromElsewhere(block.Size)
+						}
+						found = true
 						break
 					}
-					if fi.Name == state.file.Name {
-						state.copiedFromOrigin(block.Size)
-					} else {
-						state.copiedFromElsewhere(block.Size)
-					}
-					found = true
-					break
-				}
-				if err := errFn(); err != nil {
-					l.Warnln(err)
 				}
 			}
 

lib/model/folder_sendrecv_test.go

@@ -19,7 +19,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/syncthing/syncthing/internal/itererr"
 	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/events"
@@ -326,11 +325,11 @@ func TestCopierCleanup(t *testing.T) {
 	// Update index (removing old blocks)
 	f.updateLocalsFromScanning([]protocol.FileInfo{file})
 
-	if vals, err := itererr.Collect(m.sdb.AllLocalBlocksWithHash(blocks[0].Hash)); err != nil || len(vals) > 0 {
+	if vals, err := m.sdb.AllLocalBlocksWithHash(blocks[0].Hash); err != nil || len(vals) > 0 {
 		t.Error("Unexpected block found")
 	}
 
-	if vals, err := itererr.Collect(m.sdb.AllLocalBlocksWithHash(blocks[1].Hash)); err != nil || len(vals) == 0 {
+	if vals, err := m.sdb.AllLocalBlocksWithHash(blocks[1].Hash); err != nil || len(vals) == 0 {
 		t.Error("Expected block not found")
 	}
 
@@ -339,11 +338,11 @@ func TestCopierCleanup(t *testing.T) {
 	// Update index (removing old blocks)
 	f.updateLocalsFromScanning([]protocol.FileInfo{file})
 
-	if vals, err := itererr.Collect(m.sdb.AllLocalBlocksWithHash(blocks[0].Hash)); err != nil || len(vals) == 0 {
+	if vals, err := m.sdb.AllLocalBlocksWithHash(blocks[0].Hash); err != nil || len(vals) == 0 {
 		t.Error("Unexpected block found")
 	}
 
-	if vals, err := itererr.Collect(m.sdb.AllLocalBlocksWithHash(blocks[1].Hash)); err != nil || len(vals) > 0 {
+	if vals, err := m.sdb.AllLocalBlocksWithHash(blocks[1].Hash); err != nil || len(vals) > 0 {
 		t.Error("Expected block not found")
 	}
 }