diff --git a/internal/commands/cluster_register.go b/internal/commands/cluster_register.go
index 4ff345036..a001aae3b 100644
--- a/internal/commands/cluster_register.go
+++ b/internal/commands/cluster_register.go
@@ -23,6 +23,7 @@ import (
 	clusternode "github.com/photoprism/photoprism/internal/service/cluster/node"
 	"github.com/photoprism/photoprism/internal/service/cluster/theme"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/http/header"
 	"github.com/photoprism/photoprism/pkg/log/status"
@@ -449,7 +450,7 @@ func persistRegisterResponse(conf *config.Config, resp *cluster.RegisterResponse
 
 	// DB settings (MySQL/MariaDB only)
 	if resp.Database.Name != "" && resp.Database.User != "" {
-		updates.SetDatabaseDriver(config.MySQL)
+		updates.SetDatabaseDriver(enum.MySQL)
 		updates.SetDatabaseName(resp.Database.Name)
 		updates.SetDatabaseServer(fmt.Sprintf("%s:%d", resp.Database.Host, resp.Database.Port))
 		updates.SetDatabaseUser(resp.Database.User)
diff --git a/internal/config/config.go b/internal/config/config.go
index 7dfdf6a4f..d45275505 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -61,6 +61,7 @@ import (
 	"github.com/photoprism/photoprism/internal/thumb"
 	"github.com/photoprism/photoprism/pkg/checksum"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/i18n"
 	"github.com/photoprism/photoprism/pkg/rnd"
@@ -688,7 +689,7 @@ func (c *Config) IndexWorkers() int {
 	}
 
 	// Limit number of workers when using SQLite3 to avoid database locking issues.
-	if c.DatabaseDriver() == SQLite3 && (cores >= 8 && c.options.IndexWorkers <= 0 || c.options.IndexWorkers > 4) {
+	if c.DatabaseDriver() == enum.SQLite3 && (cores >= 8 && c.options.IndexWorkers <= 0 || c.options.IndexWorkers > 4) {
 		return 4
 	}
 
diff --git a/internal/config/config_db.go b/internal/config/config_db.go
index 3f8698d15..e90255cd4 100644
--- a/internal/config/config_db.go
+++ b/internal/config/config_db.go
@@ -22,35 +22,26 @@ import (
 	"github.com/photoprism/photoprism/internal/service/cluster"
 	"github.com/photoprism/photoprism/pkg/clean"
 	"github.com/photoprism/photoprism/pkg/dsn"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/txt"
 )
 
-// SQL Databases.
-// TODO: PostgreSQL support requires upgrading GORM, so generic column data types can be used.
-const (
-	Auto     = "auto"
-	MySQL    = dsn.DriverMySQL
-	MariaDB  = dsn.DriverMariaDB
-	Postgres = dsn.DriverPostgres
-	SQLite3  = dsn.DriverSQLite3
-)
-
 // DatabaseDriver returns the database driver name.
 func (c *Config) DatabaseDriver() string {
 	c.normalizeDatabaseDSN()
 
 	switch strings.ToLower(c.options.DatabaseDriver) {
-	case MySQL, MariaDB:
-		c.options.DatabaseDriver = MySQL
-	case SQLite3, "sqlite", "test", "file", "":
-		c.options.DatabaseDriver = SQLite3
+	case enum.MySQL, enum.MariaDB:
+		c.options.DatabaseDriver = enum.MySQL
+	case enum.SQLite3, "sqlite", "test", "file", "":
+		c.options.DatabaseDriver = enum.SQLite3
 	case "tidb":
 		log.Warnf("config: database driver 'tidb' is deprecated, using sqlite")
-		c.options.DatabaseDriver = SQLite3
+		c.options.DatabaseDriver = enum.SQLite3
 		c.options.DatabaseDSN = ""
 	default:
 		log.Warnf("config: unsupported database driver %s, using sqlite", c.options.DatabaseDriver)
-		c.options.DatabaseDriver = SQLite3
+		c.options.DatabaseDriver = enum.SQLite3
 		c.options.DatabaseDSN = ""
 	}
 
@@ -60,9 +51,9 @@ func (c *Config) DatabaseDriver() string {
 // DatabaseDriverName returns the formatted database driver name.
 func (c *Config) DatabaseDriverName() string {
 	switch c.DatabaseDriver() {
-	case MySQL, MariaDB:
+	case enum.MySQL, enum.MariaDB:
 		return "MariaDB"
-	case SQLite3, "sqlite", "test", "file", "":
+	case enum.SQLite3, "sqlite", "test", "file", "":
 		return "SQLite"
 	case "tidb":
 		return "TiDB"
@@ -92,7 +83,7 @@ func (c *Config) DatabaseSsl() bool {
 	}
 
 	switch c.DatabaseDriver() {
-	case MySQL:
+	case enum.MySQL:
 		// see https://mariadb.org/mission-impossible-zero-configuration-ssl/
 		return c.IsDatabaseVersion("v11.4")
 	default:
@@ -115,7 +106,7 @@ func (c *Config) DatabaseDSN() string {
 	// Generate matching database DSN based on the configured database driver.
 	if c.NoDatabaseDSN() {
 		switch c.DatabaseDriver() {
-		case MySQL:
+		case enum.MySQL:
 			databaseServer := c.DatabaseServer()
 
 			// Connect via Unix Domain Socket?
@@ -132,10 +123,10 @@ func (c *Config) DatabaseDSN() string {
 				c.DatabasePassword(),
 				databaseServer,
 				c.DatabaseName(),
-				dsn.Params[dsn.DriverMySQL],
+				dsn.Params[enum.MySQL],
 				c.DatabaseTimeout(),
 			)
-		case Postgres:
+		case enum.Postgres:
 			return fmt.Sprintf(
 				"user=%s password=%s dbname=%s host=%s port=%d connect_timeout=%d %s",
 				c.DatabaseUser(),
@@ -144,10 +135,10 @@ func (c *Config) DatabaseDSN() string {
 				c.DatabaseHost(),
 				c.DatabasePort(),
 				c.DatabaseTimeout(),
-				dsn.Params[dsn.DriverPostgres],
+				dsn.Params[enum.Postgres],
 			)
-		case SQLite3:
-			return filepath.Join(c.StoragePath(), fmt.Sprintf("index.db?%s", dsn.Params[dsn.DriverSQLite3]))
+		case enum.SQLite3:
+			return filepath.Join(c.StoragePath(), fmt.Sprintf("index.db?%s", dsn.Params[enum.SQLite3]))
 		default:
 			log.Errorf("config: empty database dsn")
 			return ""
@@ -155,11 +146,11 @@ func (c *Config) DatabaseDSN() string {
 	}
 
 	// If missing, add the required parameters to the configured MySQL/MariaDB DSN.
-	if c.DatabaseDriver() == MySQL && !strings.Contains(c.options.DatabaseDSN, "?") {
+	if c.DatabaseDriver() == enum.MySQL && !strings.Contains(c.options.DatabaseDSN, "?") {
 		c.options.DatabaseDSN = fmt.Sprintf(
 			"%s?%s&timeout=%ds",
 			c.options.DatabaseDSN,
-			dsn.Params[dsn.DriverMySQL],
+			dsn.Params[enum.MySQL],
 			c.DatabaseTimeout())
 	}
 
@@ -181,7 +172,7 @@ func (c *Config) HasDatabaseDSN() bool {
 // ReportDatabaseDSN checks if the database data source name (DSN) should be reported
 // instead of database name, server, user, and password.
 func (c *Config) ReportDatabaseDSN() bool {
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return true
 	}
 
@@ -192,7 +183,7 @@ func (c *Config) ReportDatabaseDSN() bool {
 func (c *Config) ParseDatabaseDSN() {
 	if c.NoDatabaseDSN() {
 		return
-	} else if c.options.DatabaseServer != "" && c.DatabaseDriver() == SQLite3 {
+	} else if c.options.DatabaseServer != "" && c.DatabaseDriver() == enum.SQLite3 {
 		return
 	}
 
@@ -214,7 +205,7 @@ func (c *Config) DatabaseFile() string {
 func (c *Config) DatabaseServer() string {
 	c.ParseDatabaseDSN()
 
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return ""
 	} else if c.options.DatabaseServer == "" {
 		return localhost
@@ -227,7 +218,7 @@ func (c *Config) DatabaseServer() string {
 func (c *Config) DatabaseHost() string {
 	c.ParseDatabaseDSN()
 
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return ""
 	}
 
@@ -239,7 +230,7 @@ func (c *Config) DatabaseHost() string {
 func (c *Config) DatabasePort() int {
 	c.ParseDatabaseDSN()
 
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return 0
 	}
 
@@ -249,7 +240,7 @@ func (c *Config) DatabasePort() int {
 
 // DatabasePortString the database server port as string.
 func (c *Config) DatabasePortString() string {
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return ""
 	}
 
@@ -260,7 +251,7 @@ func (c *Config) DatabasePortString() string {
 func (c *Config) DatabaseName() string {
 	c.ParseDatabaseDSN()
 
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return c.DatabaseDSN()
 	} else if c.options.DatabaseName == "" {
 		return "photoprism"
@@ -271,7 +262,7 @@ func (c *Config) DatabaseName() string {
 
 // DatabaseUser returns the database user name.
 func (c *Config) DatabaseUser() string {
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return ""
 	}
 
@@ -286,7 +277,7 @@ func (c *Config) DatabaseUser() string {
 
 // DatabasePassword returns the database user password.
 func (c *Config) DatabasePassword() string {
-	if c.DatabaseDriver() == SQLite3 {
+	if c.DatabaseDriver() == enum.SQLite3 {
 		return ""
 	}
 
@@ -358,7 +349,7 @@ func (c *Config) DatabaseProvisionPrefix() string {
 // ShouldAutoRotateDatabase decides whether callers should request DB rotation automatically.
 // It is used by both the CLI and node bootstrap to avoid unnecessary provisioning calls.
 func (c *Config) ShouldAutoRotateDatabase() bool {
-	if c.Portal() || c.DatabaseDriver() != MySQL {
+	if c.Portal() || c.DatabaseDriver() != enum.MySQL {
 		return false
 	}
 
@@ -440,11 +431,11 @@ func (c *Config) CloseDb() error {
 // SetDbOptions sets the database collation to unicode if supported.
 func (c *Config) SetDbOptions() {
 	switch c.DatabaseDriver() {
-	case MySQL, MariaDB:
+	case enum.MySQL, enum.MariaDB:
 		c.Db().Set("gorm:table_options", "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci")
-	case Postgres:
+	case enum.Postgres:
 		// Ignore for now.
-	case SQLite3:
+	case enum.SQLite3:
 		// Not required as Unicode is default.
 	}
 }
@@ -515,7 +506,7 @@ func (c *Config) checkDb(db *gorm.DB) error {
 	}
 
 	switch c.DatabaseDriver() {
-	case MySQL:
+	case enum.MySQL:
 		type Res struct {
 			Value string `gorm:"column:Value;"`
 		}
@@ -544,7 +535,7 @@ func (c *Config) checkDb(db *gorm.DB) error {
 		case !c.IsDatabaseVersion("v10.5.12"):
 			return fmt.Errorf("config: MariaDB %s is not supported, see https://docs.photoprism.app/getting-started/#databases", c.dbVersion)
 		}
-	case SQLite3:
+	case enum.SQLite3:
 		type Res struct {
 			Value string `gorm:"column:Value;"`
 		}
diff --git a/internal/config/config_db_test.go b/internal/config/config_db_test.go
index 6b2013544..284b6163f 100644
--- a/internal/config/config_db_test.go
+++ b/internal/config/config_db_test.go
@@ -6,6 +6,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"github.com/photoprism/photoprism/pkg/enum"
+
 	"github.com/photoprism/photoprism/internal/service/cluster"
 )
 
@@ -26,16 +28,16 @@ func TestConfig_DatabaseDriver(t *testing.T) {
 		c := NewConfig(CliTestContext())
 		resetDatabaseOptions(c)
 
-		assert.Equal(t, SQLite3, c.DatabaseDriver())
+		assert.Equal(t, enum.SQLite3, c.DatabaseDriver())
 	})
 	t.Run("NormalizesDeprecatedDSN", func(t *testing.T) {
 		c := NewConfig(CliTestContext())
 		resetDatabaseOptions(c)
 
-		c.options.DatabaseDriver = MySQL
+		c.options.DatabaseDriver = enum.MySQL
 		c.options.Deprecated.DatabaseDsn = "user:pass@tcp(localhost:3306)/photoprism"
 
-		assert.Equal(t, MySQL, c.DatabaseDriver())
+		assert.Equal(t, enum.MySQL, c.DatabaseDriver())
 		assert.Equal(t, "user:pass@tcp(localhost:3306)/photoprism", c.options.DatabaseDSN)
 		assert.Empty(t, c.options.Deprecated.DatabaseDsn)
 	})
@@ -65,7 +67,7 @@ func TestConfig_normalizeDatabaseDSN(t *testing.T) {
 	c := NewConfig(CliTestContext())
 
 	c.options.Deprecated.DatabaseDsn = "foo:b@r@tcp(honeypot:1234)/baz?charset=utf8mb4,utf8&parseTime=true"
-	c.options.DatabaseDriver = MySQL
+	c.options.DatabaseDriver = enum.MySQL
 
 	assert.Equal(t, "honeypot:1234", c.DatabaseServer())
 	assert.Equal(t, "honeypot", c.DatabaseHost())
@@ -79,7 +81,7 @@ func TestConfig_ParseDatabaseDSN(t *testing.T) {
 	c := NewConfig(CliTestContext())
 
 	c.options.DatabaseDSN = "foo:b@r@tcp(honeypot:1234)/baz?charset=utf8mb4,utf8&parseTime=true"
-	c.options.DatabaseDriver = SQLite3
+	c.options.DatabaseDriver = enum.SQLite3
 
 	assert.Equal(t, "", c.DatabaseServer())
 	assert.Equal(t, "", c.DatabaseHost())
@@ -88,7 +90,7 @@ func TestConfig_ParseDatabaseDSN(t *testing.T) {
 	assert.Equal(t, "", c.DatabaseUser())
 	assert.Equal(t, "", c.DatabasePassword())
 
-	c.options.DatabaseDriver = MySQL
+	c.options.DatabaseDriver = enum.MySQL
 
 	assert.Equal(t, "honeypot:1234", c.DatabaseServer())
 	assert.Equal(t, "honeypot", c.DatabaseHost())
@@ -97,7 +99,7 @@ func TestConfig_ParseDatabaseDSN(t *testing.T) {
 	assert.Equal(t, "foo", c.DatabaseUser())
 	assert.Equal(t, "b@r", c.DatabasePassword())
 
-	c.options.DatabaseDriver = SQLite3
+	c.options.DatabaseDriver = enum.SQLite3
 
 	assert.Equal(t, "", c.DatabaseServer())
 	assert.Equal(t, "", c.DatabaseHost())
@@ -110,7 +112,7 @@ func TestConfig_ParseDatabaseDSN(t *testing.T) {
 		target := NewConfig(CliTestContext())
 		resetDatabaseOptions(target)
 
-		target.options.DatabaseDriver = MySQL
+		target.options.DatabaseDriver = enum.MySQL
 		target.options.DatabaseServer = "db.internal:3306"
 		target.options.DatabaseName = "photoprism"
 		target.options.DatabaseUser = "app"
@@ -129,7 +131,7 @@ func TestConfig_ParseDatabaseDSN(t *testing.T) {
 		cfg := NewConfig(CliTestContext())
 		resetDatabaseOptions(cfg)
 
-		cfg.options.DatabaseDriver = SQLite3
+		cfg.options.DatabaseDriver = enum.SQLite3
 		cfg.options.DatabaseDSN = "file:/data/app.db?_busy_timeout=5000"
 		cfg.options.DatabaseServer = "/tmp/mysql.sock"
 		cfg.options.DatabaseName = "existing-name"
@@ -191,9 +193,9 @@ func TestConfig_DatabasePassword(t *testing.T) {
 	// Test setting the password via secret file.
 	_ = os.Setenv(FlagFileVar("DATABASE_PASSWORD"), "testdata/secret_database")
 	assert.Equal(t, "", c.DatabasePassword())
-	c.Options().DatabaseDriver = MySQL
+	c.Options().DatabaseDriver = enum.MySQL
 	assert.Equal(t, "StoryOfAmélie", c.DatabasePassword())
-	c.Options().DatabaseDriver = SQLite3
+	c.Options().DatabaseDriver = enum.SQLite3
 	_ = os.Setenv(FlagFileVar("DATABASE_PASSWORD"), "")
 
 	assert.Equal(t, "", c.DatabasePassword())
@@ -222,19 +224,19 @@ func TestShouldAutoRotateDatabase(t *testing.T) {
 	t.Run("PortalAlwaysFalse", func(t *testing.T) {
 		conf := NewMinimalTestConfig(t.TempDir())
 		conf.Options().NodeRole = cluster.RolePortal
-		conf.Options().DatabaseDriver = MySQL
+		conf.Options().DatabaseDriver = enum.MySQL
 		assert.False(t, conf.ShouldAutoRotateDatabase())
 	})
 
 	t.Run("NonMySQLDriverFalse", func(t *testing.T) {
 		conf := NewMinimalTestConfig(t.TempDir())
-		conf.Options().DatabaseDriver = SQLite3
+		conf.Options().DatabaseDriver = enum.SQLite3
 		assert.False(t, conf.ShouldAutoRotateDatabase())
 	})
 
 	t.Run("MySQLMissingFieldsTrue", func(t *testing.T) {
 		conf := NewMinimalTestConfig(t.TempDir())
-		conf.Options().DatabaseDriver = MySQL
+		conf.Options().DatabaseDriver = enum.MySQL
 		conf.Options().DatabaseName = "photoprism"
 		conf.Options().DatabaseUser = ""
 		conf.Options().DatabasePassword = ""
@@ -246,7 +248,7 @@ func TestConfig_DatabaseDSN(t *testing.T) {
 	c := NewConfig(CliTestContext())
 	resetDatabaseOptions(c)
 	driver := c.DatabaseDriver()
-	assert.Equal(t, SQLite3, driver)
+	assert.Equal(t, enum.SQLite3, driver)
 	c.options.DatabaseDSN = ""
 	c.options.DatabaseDriver = "MariaDB"
 	assert.Equal(t, "photoprism:@tcp(localhost)/photoprism?charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true&timeout=15s", c.DatabaseDSN())
@@ -263,7 +265,7 @@ func TestConfig_DatabaseDSN(t *testing.T) {
 		conf := NewConfig(CliTestContext())
 		resetDatabaseOptions(conf)
 
-		conf.options.DatabaseDriver = MySQL
+		conf.options.DatabaseDriver = enum.MySQL
 		conf.options.DatabaseServer = "proxy.internal:6032"
 		conf.options.DatabaseName = "tenantdb"
 		conf.options.DatabaseUser = "tenant"
@@ -279,7 +281,7 @@ func TestConfig_DatabaseDSN(t *testing.T) {
 		conf := NewConfig(CliTestContext())
 		resetDatabaseOptions(conf)
 
-		conf.options.DatabaseDriver = MySQL
+		conf.options.DatabaseDriver = enum.MySQL
 		conf.options.DatabaseServer = "/var/run/mysql.sock"
 		conf.options.DatabaseName = "tenantdb"
 		conf.options.DatabaseUser = "tenant"
@@ -305,7 +307,7 @@ func TestConfig_DatabaseDSNFlags(t *testing.T) {
 		conf := NewConfig(CliTestContext())
 		resetDatabaseOptions(conf)
 
-		conf.options.DatabaseDriver = MySQL
+		conf.options.DatabaseDriver = enum.MySQL
 		conf.options.Deprecated.DatabaseDsn = "user:pass@tcp(db.internal:3306)/photoprism"
 
 		assert.False(t, conf.NoDatabaseDSN())
@@ -319,10 +321,10 @@ func TestConfig_ReportDatabaseDSN(t *testing.T) {
 	conf := NewConfig(CliTestContext())
 	resetDatabaseOptions(conf)
 
-	assert.Equal(t, SQLite3, conf.DatabaseDriver())
+	assert.Equal(t, enum.SQLite3, conf.DatabaseDriver())
 	assert.True(t, conf.ReportDatabaseDSN())
 
-	conf.options.DatabaseDriver = MySQL
+	conf.options.DatabaseDriver = enum.MySQL
 	conf.options.DatabaseDSN = ""
 	assert.False(t, conf.ReportDatabaseDSN())
 
@@ -335,7 +337,7 @@ func TestConfig_DatabaseFile(t *testing.T) {
 	// Ensure SQLite defaults
 	resetDatabaseOptions(c)
 	driver := c.DatabaseDriver()
-	assert.Equal(t, SQLite3, driver)
+	assert.Equal(t, enum.SQLite3, driver)
 	c.options.DatabaseDSN = ""
 	assert.Equal(t, ProjectRoot+"/storage/testdata/index.db", c.DatabaseFile())
 	assert.Equal(t, ProjectRoot+"/storage/testdata/index.db?_busy_timeout=5000", c.DatabaseDSN())
diff --git a/internal/config/config_thumb_test.go b/internal/config/config_thumb_test.go
index 0db6bf2f7..d894e575d 100644
--- a/internal/config/config_thumb_test.go
+++ b/internal/config/config_thumb_test.go
@@ -6,6 +6,7 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/photoprism/photoprism/internal/thumb"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 func TestConfig_ConvertSize(t *testing.T) {
@@ -48,7 +49,7 @@ func TestConfig_ThumbFilter(t *testing.T) {
 	assert.Equal(t, thumb.ResampleLanczos, c.ThumbFilter())
 	c.options.ThumbFilter = "linear"
 	assert.Equal(t, thumb.ResampleLinear, c.ThumbFilter())
-	c.options.ThumbFilter = Auto
+	c.options.ThumbFilter = enum.Auto
 	assert.Equal(t, thumb.ResampleLanczos, c.ThumbFilter())
 	c.options.ThumbFilter = ""
 	assert.Equal(t, thumb.ResampleLanczos, c.ThumbFilter())
@@ -92,7 +93,7 @@ func TestConfig_PngSize(t *testing.T) {
 func TestConfig_ThumbLibrary(t *testing.T) {
 	c := NewConfig(CliTestContext())
 	assert.False(t, c.DisableVips())
-	c.options.ThumbLibrary = Auto
+	c.options.ThumbLibrary = enum.Auto
 	assert.Equal(t, "vips", c.ThumbLibrary())
 	c.options.DisableVips = true
 	assert.Equal(t, "imaging", c.ThumbLibrary())
diff --git a/internal/config/flags.go b/internal/config/flags.go
index b2c32c31f..2acaea8c3 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -15,6 +15,7 @@ import (
 	"github.com/photoprism/photoprism/internal/service/hub/places"
 	"github.com/photoprism/photoprism/internal/thumb"
 	"github.com/photoprism/photoprism/pkg/authn"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/http/header"
 	"github.com/photoprism/photoprism/pkg/http/scheme"
@@ -941,7 +942,7 @@ var Flags = CliFlags{
 		Flag: &cli.StringFlag{
 			Name:    "database-provision-driver",
 			Usage:   "auto-provisioning `DRIVER` (auto, mysql)",
-			Value:   Auto,
+			Value:   enum.Auto,
 			EnvVars: EnvVars("DATABASE_PROVISION_DRIVER"),
 			Hidden:  true,
 		}}, {
@@ -1113,7 +1114,7 @@ var Flags = CliFlags{
 			Name:    "thumb-library",
 			Aliases: []string{"thumbs"},
 			Usage:   "image processing `LIBRARY` to be used for generating thumbnails (auto, imaging, vips)",
-			Value:   Auto,
+			Value:   enum.Auto,
 			EnvVars: EnvVars("THUMB_LIBRARY"),
 		}}, {
 		Flag: &cli.StringFlag{
diff --git a/internal/config/report_test.go b/internal/config/report_test.go
index d02a55697..f1286cdab 100644
--- a/internal/config/report_test.go
+++ b/internal/config/report_test.go
@@ -5,6 +5,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 func TestConfig_Report(t *testing.T) {
@@ -34,7 +36,7 @@ func TestConfig_ReportDatabaseSection(t *testing.T) {
 		rows, _ := conf.Report()
 		values := collect(rows)
 
-		assert.Equal(t, SQLite3, values["database-driver"])
+		assert.Equal(t, enum.SQLite3, values["database-driver"])
 		assert.Equal(t, conf.DatabaseDSN(), values["database-dsn"])
 		_, hasName := values["database-name"]
 		assert.False(t, hasName)
@@ -43,7 +45,7 @@ func TestConfig_ReportDatabaseSection(t *testing.T) {
 		conf := NewConfig(CliTestContext())
 		resetDatabaseOptions(conf)
 
-		conf.options.DatabaseDriver = MySQL
+		conf.options.DatabaseDriver = enum.MySQL
 		conf.options.DatabaseServer = "db.internal:3306"
 		conf.options.DatabaseName = "photoprism"
 		conf.options.DatabaseUser = "app"
@@ -52,7 +54,7 @@ func TestConfig_ReportDatabaseSection(t *testing.T) {
 		rows, _ := conf.Report()
 		values := collect(rows)
 
-		assert.Equal(t, MySQL, values["database-driver"])
+		assert.Equal(t, enum.MySQL, values["database-driver"])
 		assert.Equal(t, "photoprism", values["database-name"])
 		assert.Equal(t, "db.internal:3306", values["database-server"])
 		assert.Equal(t, "db.internal", values["database-host"])
@@ -66,13 +68,13 @@ func TestConfig_ReportDatabaseSection(t *testing.T) {
 		conf := NewConfig(CliTestContext())
 		resetDatabaseOptions(conf)
 
-		conf.options.DatabaseDriver = MySQL
+		conf.options.DatabaseDriver = enum.MySQL
 		conf.options.DatabaseDSN = "user:pass@tcp(db.internal:3306)/photoprism"
 
 		rows, _ := conf.Report()
 		values := collect(rows)
 
-		assert.Equal(t, MySQL, values["database-driver"])
+		assert.Equal(t, enum.MySQL, values["database-driver"])
 		assert.Equal(t, "user:***@tcp(db.internal:3306)/photoprism?charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true&timeout=15s", values["database-dsn"])
 		_, hasName := values["database-name"]
 		assert.False(t, hasName)
diff --git a/internal/config/test.go b/internal/config/test.go
index dd8d864f3..c5fa27801 100644
--- a/internal/config/test.go
+++ b/internal/config/test.go
@@ -23,7 +23,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/authn"
 	"github.com/photoprism/photoprism/pkg/capture"
 	"github.com/photoprism/photoprism/pkg/clean"
-	"github.com/photoprism/photoprism/pkg/dsn"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/rnd"
 	"github.com/photoprism/photoprism/pkg/txt/report"
@@ -127,19 +127,19 @@ func NewTestOptionsForPath(dbName, dataPath string) *Options {
 
 	// Set default test database driver.
 	if testDriver == "test" || testDriver == "sqlite" || testDriver == "" || testDsn == "" {
-		testDriver = dsn.DriverSQLite3
+		testDriver = enum.SQLite3
 	}
 
 	// Set default database DSN.
-	if testDriver == dsn.DriverSQLite3 {
+	if testDriver == enum.SQLite3 {
 		if testDsn == "" && dbName != "" {
 			if testDsn = fmt.Sprintf(".%s.db", clean.TypeLower(dbName)); !fs.FileExists(testDsn) {
 				log.Tracef("sqlite: test database %s does not already exist", clean.Log(testDsn))
 			} else if err := os.Remove(testDsn); err != nil {
 				log.Errorf("sqlite: failed to remove existing test database %s (%s)", clean.Log(testDsn), err)
 			}
-		} else if testDsn == "" || testDsn == dsn.SQLiteTestDB {
-			testDsn = dsn.SQLiteTestDB
+		} else if testDsn == "" || testDsn == enum.SQLiteTestDB {
+			testDsn = enum.SQLiteTestDB
 			if !fs.FileExists(testDsn) {
 				log.Tracef("sqlite: test database %s does not already exist", clean.Log(testDsn))
 			} else if err := os.Remove(testDsn); err != nil {
@@ -205,7 +205,7 @@ func NewTestOptionsError() *Options {
 		OriginalsPath:  dataPath + "/originals",
 		ImportPath:     dataPath + "/import",
 		TempPath:       dataPath + "/temp",
-		DatabaseDriver: SQLite3,
+		DatabaseDriver: enum.SQLite3,
 		DatabaseDSN:    ".test-error.db",
 	}
 
@@ -244,7 +244,7 @@ func NewMinimalTestConfigWithDb(dbName, dataPath string) *Config {
 	cachedDb := false
 
 	// Try to restore test db from cache.
-	if len(testDbCache) > 0 && c.DatabaseDriver() == SQLite3 && !fs.FileExists(c.DatabaseDSN()) {
+	if len(testDbCache) > 0 && c.DatabaseDriver() == enum.SQLite3 && !fs.FileExists(c.DatabaseDSN()) {
 		if err := os.WriteFile(c.DatabaseDSN(), testDbCache, fs.ModeFile); err != nil {
 			log.Warnf("config: %s (restore test database)", err)
 		} else {
@@ -264,7 +264,7 @@ func NewMinimalTestConfigWithDb(dbName, dataPath string) *Config {
 
 	c.InitTestDb()
 
-	if testDbCache == nil && c.DatabaseDriver() == SQLite3 && fs.FileExistsNotEmpty(c.DatabaseDSN()) {
+	if testDbCache == nil && c.DatabaseDriver() == enum.SQLite3 && fs.FileExistsNotEmpty(c.DatabaseDSN()) {
 		testDbMutex.Lock()
 		defer testDbMutex.Unlock()
 
diff --git a/internal/entity/db_conn.go b/internal/entity/db_conn.go
index 14d83a92b..4f3bc77ab 100644
--- a/internal/entity/db_conn.go
+++ b/internal/entity/db_conn.go
@@ -8,16 +8,6 @@ import (
 	"github.com/jinzhu/gorm"
 	_ "github.com/jinzhu/gorm/dialects/mysql"
 	_ "github.com/jinzhu/gorm/dialects/sqlite"
-
-	"github.com/photoprism/photoprism/pkg/dsn"
-)
-
-// Supported test databases.
-const (
-	MySQL           = dsn.DriverMySQL
-	SQLite3         = dsn.DriverSQLite3
-	SQLiteTestDB    = ".test.db"
-	SQLiteMemoryDSN = ":memory:?cache=shared"
 )
 
 // dbConn is the global gorm.DB connection provider.
diff --git a/internal/entity/entity_counts.go b/internal/entity/entity_counts.go
index ad885f83d..fee587d85 100644
--- a/internal/entity/entity_counts.go
+++ b/internal/entity/entity_counts.go
@@ -11,6 +11,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/mutex"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/time/unix"
 )
 
@@ -103,7 +104,7 @@ func UpdateSubjectCounts(public bool) (err error) {
 	condition := gorm.Expr("subj_type = ?", SubjPerson)
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE ? LEFT JOIN (
 		SELECT m.subj_uid, COUNT(DISTINCT f.id) AS subj_files, COUNT(DISTINCT f.photo_id) AS subj_photos
 			FROM files f
@@ -114,7 +115,7 @@ func UpdateSubjectCounts(public bool) (err error) {
 		SET subjects.file_count = CASE WHEN b.subj_files IS NULL THEN 0 ELSE b.subj_files END, 
 			subjects.photo_count = CASE WHEN b.subj_photos IS NULL THEN 0 ELSE b.subj_photos END
 		WHERE ?`, gorm.Expr(subjTable), photosJoin, condition)
-	case SQLite3:
+	case enum.SQLite3:
 		// Update files count.
 		res = Db().Table(subjTable).
 			UpdateColumn("file_count", gorm.Expr("(SELECT COUNT(DISTINCT f.id)"+
@@ -187,7 +188,7 @@ func UpdateLabelCounts() (err error) {
 
 	start := time.Now()
 	var res *gorm.DB
-	if IsDialect(MySQL) {
+	if IsDialect(enum.MySQL) {
 		res = Db().Exec(`UPDATE labels LEFT JOIN (
 		SELECT p2.label_id, COUNT(DISTINCT photo_id) AS label_photos FROM (
 			SELECT pl.label_id as label_id, p.id AS photo_id FROM photos p
@@ -201,7 +202,7 @@ func UpdateLabelCounts() (err error) {
 			) p2 GROUP BY p2.label_id
 		) b ON b.label_id = labels.id
 		SET photo_count = CASE WHEN b.label_photos IS NULL THEN 0 ELSE b.label_photos END`)
-	} else if IsDialect(SQLite3) {
+	} else if IsDialect(enum.SQLite3) {
 		res = Db().
 			Table("labels").
 			UpdateColumn("photo_count",
diff --git a/internal/entity/entity_init.go b/internal/entity/entity_init.go
index 488c80465..13c10e30c 100644
--- a/internal/entity/entity_init.go
+++ b/internal/entity/entity_init.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/entity/migrate"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
@@ -55,13 +56,13 @@ func InitTestDb(driver, dbDsn string) *DbConn {
 
 	// Set default test database driver.
 	if driver == "test" || driver == "sqlite" || driver == "" || dbDsn == "" {
-		driver = SQLite3
+		driver = enum.SQLite3
 	}
 
 	// Set default database DSN.
-	if driver == SQLite3 {
-		if dbDsn == "" || dbDsn == SQLiteTestDB {
-			dbDsn = SQLiteTestDB
+	if driver == enum.SQLite3 {
+		if dbDsn == "" || dbDsn == enum.SQLiteTestDB {
+			dbDsn = enum.SQLiteTestDB
 			if !fs.FileExists(dbDsn) {
 				log.Debugf("sqlite: test database %s does not already exist", clean.Log(dbDsn))
 			} else if err := os.Remove(dbDsn); err != nil {
diff --git a/internal/entity/face.go b/internal/entity/face.go
index c57c849c0..42d6f308c 100644
--- a/internal/entity/face.go
+++ b/internal/entity/face.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/photoprism/photoprism/internal/ai/face"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
 
@@ -340,7 +341,7 @@ func (m *Face) RefreshPhotos() error {
 
 	var err error
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		update := fmt.Sprintf(`UPDATE photos p JOIN files f ON f.photo_id = p.id JOIN %s m ON m.file_uid = f.file_uid
 			SET p.checked_at = NULL WHERE m.face_id = ?`, Marker{}.TableName())
 		err = UnscopedDb().Exec(update, m.ID).Error
diff --git a/internal/entity/file.go b/internal/entity/file.go
index 066571081..04d5aa1de 100644
--- a/internal/entity/file.go
+++ b/internal/entity/file.go
@@ -17,6 +17,7 @@ import (
 	"github.com/photoprism/photoprism/internal/ai/face"
 	"github.com/photoprism/photoprism/internal/config/customize"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/media"
 	"github.com/photoprism/photoprism/pkg/media/colors"
@@ -129,7 +130,7 @@ func (m File) RegenerateIndex() {
 	}
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		Log("files", "regenerate photo_taken_at",
 			Db().Exec("UPDATE files JOIN ? p ON p.id = files.photo_id SET files.photo_taken_at = p.taken_at_local WHERE ?",
 				gorm.Expr(photosTable), updateWhere).Error)
@@ -141,7 +142,7 @@ func (m File) RegenerateIndex() {
 		Log("files", "regenerate time_index",
 			Db().Exec("UPDATE files SET time_index = CASE WHEN media_id IS NOT NULL AND photo_taken_at IS NOT NULL THEN CONCAT(100000000000000 - CAST(photo_taken_at AS UNSIGNED), '-', media_id) ELSE NULL END WHERE ?",
 				updateWhere).Error)
-	case SQLite3:
+	case enum.SQLite3:
 		Log("files", "regenerate photo_taken_at",
 			Db().Exec("UPDATE files SET photo_taken_at = (SELECT p.taken_at_local FROM ? p WHERE p.id = photo_id) WHERE ?",
 				gorm.Expr(photosTable), updateWhere).Error)
diff --git a/internal/entity/marker.go b/internal/entity/marker.go
index 90f8a6537..c6e3e1290 100644
--- a/internal/entity/marker.go
+++ b/internal/entity/marker.go
@@ -14,6 +14,7 @@ import (
 	"github.com/photoprism/photoprism/internal/form"
 	"github.com/photoprism/photoprism/internal/thumb/crop"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
 
@@ -575,7 +576,7 @@ func (m *Marker) RefreshPhotos() error {
 
 	var err error
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		err = UnscopedDb().Exec(`UPDATE photos p JOIN files f ON f.photo_id = p.id
 			JOIN ? m ON m.file_uid = f.file_uid SET p.checked_at = NULL
 			WHERE m.marker_uid = ?`,
diff --git a/internal/entity/migrate/dialects.go b/internal/entity/migrate/dialects.go
index 9ee0d400e..41cd23b62 100644
--- a/internal/entity/migrate/dialects.go
+++ b/internal/entity/migrate/dialects.go
@@ -1,19 +1,17 @@
 package migrate
 
-import "sync"
+import (
+	"sync"
 
-// Supported database dialects.
-const (
-	MySQL   = "mysql"
-	SQLite3 = "sqlite3"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 var Dialects = map[string]Migrations{
-	MySQL:   DialectMySQL,
-	SQLite3: DialectSQLite3,
+	enum.MySQL:   DialectMySQL,
+	enum.SQLite3: DialectSQLite3,
 }
 
 var once = map[string]*sync.Once{
-	MySQL:   {},
-	SQLite3: {},
+	enum.MySQL:   {},
+	enum.SQLite3: {},
 }
diff --git a/internal/entity/mysql8_test.go b/internal/entity/mysql8_test.go
index 3ce57e920..7c6842fbc 100644
--- a/internal/entity/mysql8_test.go
+++ b/internal/entity/mysql8_test.go
@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/photoprism/photoprism/internal/entity/migrate"
+	"github.com/photoprism/photoprism/pkg/enum"
 
 	"github.com/jinzhu/gorm"
 )
@@ -17,7 +18,7 @@ func TestMySQL8(t *testing.T) {
 		t.Skip("skipping MySQL 8 test: PHOTOPRISM_TEST_DSN_MYSQL8 is not set")
 	}
 
-	dbDriver := MySQL
+	dbDriver := enum.MySQL
 	db, err := gorm.Open(dbDriver, dbDsn)
 
 	if err != nil || db == nil {
diff --git a/internal/entity/photo_estimate.go b/internal/entity/photo_estimate.go
index 76c361976..d04f43053 100644
--- a/internal/entity/photo_estimate.go
+++ b/internal/entity/photo_estimate.go
@@ -6,6 +6,7 @@ import (
 	"github.com/jinzhu/gorm"
 
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/geo"
 	"github.com/photoprism/photoprism/pkg/txt"
@@ -99,14 +100,14 @@ func (m *Photo) EstimateLocation(force bool) {
 	var mostRecent Photos
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		err = UnscopedDb().
 			Where("photo_lat <> 0 AND photo_lng <> 0").
 			Where("place_src <> '' AND place_src <> ? AND place_id IS NOT NULL AND place_id <> '' AND place_id <> 'zz'", SrcEstimate).
 			Where("taken_src <> '' AND taken_at BETWEEN CAST(? AS DATETIME) AND CAST(? AS DATETIME)", rangeMin, rangeMax).
 			Order(gorm.Expr("ABS(TIMESTAMPDIFF(SECOND, taken_at, ?))", m.TakenAt)).Limit(2).
 			Preload("Place").Find(&mostRecent).Error
-	case SQLite3:
+	case enum.SQLite3:
 		err = UnscopedDb().
 			Where("photo_lat <> 0 AND photo_lng <> 0").
 			Where("place_src <> '' AND place_src <> ? AND place_id IS NOT NULL AND place_id <> '' AND place_id <> 'zz'", SrcEstimate).
diff --git a/internal/entity/photo_merge.go b/internal/entity/photo_merge.go
index 0fc24e146..45694b837 100644
--- a/internal/entity/photo_merge.go
+++ b/internal/entity/photo_merge.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/jinzhu/gorm"
 
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
 
@@ -108,11 +109,11 @@ func (m *Photo) Merge(mergeMeta, mergeUuid bool) (original Photo, merged Photos,
 		logResult(UnscopedDb().Exec("UPDATE photos SET photo_quality = -1, deleted_at = ? WHERE id = ?", Now(), merge.ID))
 
 		switch DbDialect() {
-		case MySQL:
+		case enum.MySQL:
 			logResult(UnscopedDb().Exec("UPDATE IGNORE photos_keywords SET photo_id = ? WHERE photo_id = ?", original.ID, merge.ID))
 			logResult(UnscopedDb().Exec("UPDATE IGNORE photos_labels SET photo_id = ? WHERE photo_id = ?", original.ID, merge.ID))
 			logResult(UnscopedDb().Exec("UPDATE IGNORE photos_albums SET photo_uid = ? WHERE photo_uid = ?", original.PhotoUID, merge.PhotoUID))
-		case SQLite3:
+		case enum.SQLite3:
 			logResult(UnscopedDb().Exec("UPDATE OR IGNORE photos_keywords SET photo_id = ? WHERE photo_id = ?", original.ID, merge.ID))
 			logResult(UnscopedDb().Exec("UPDATE OR IGNORE photos_labels SET photo_id = ? WHERE photo_id = ?", original.ID, merge.ID))
 			logResult(UnscopedDb().Exec("UPDATE OR IGNORE photos_albums SET photo_uid = ? WHERE photo_uid = ?", original.PhotoUID, merge.PhotoUID))
diff --git a/internal/entity/query/albums.go b/internal/entity/query/albums.go
index 95691da52..79c39f137 100644
--- a/internal/entity/query/albums.go
+++ b/internal/entity/query/albums.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/entity/sortby"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/media"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
@@ -120,7 +121,7 @@ func UpdateAlbumDates() error {
 	defer mutex.Index.Unlock()
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		return UnscopedDb().Exec(`UPDATE albums INNER JOIN (
              SELECT photo_path, MAX(taken_at_local) AS taken_max
 			 FROM photos WHERE taken_src = 'meta' AND photos.photo_quality >= 3 AND photos.deleted_at IS NULL
diff --git a/internal/entity/query/covers.go b/internal/entity/query/covers.go
index 54aaf7798..210d7a11c 100644
--- a/internal/entity/query/covers.go
+++ b/internal/entity/query/covers.go
@@ -12,6 +12,7 @@ import (
 	"github.com/photoprism/photoprism/internal/entity"
 	"github.com/photoprism/photoprism/internal/mutex"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/media"
 )
 
@@ -45,7 +46,7 @@ func UpdateAlbumManualCovers(albums ...entity.Album) (err error) {
 	condition := gorm.Expr("album_type = ? AND thumb_src = ?", entity.AlbumManual, entity.SrcAuto)
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE albums LEFT JOIN (
 	    	SELECT p2.album_uid, f.file_hash FROM files f, (
 	        	SELECT pa.album_uid, max(p.id) AS photo_id FROM photos p
@@ -54,7 +55,7 @@ func UpdateAlbumManualCovers(albums ...entity.Album) (err error) {
 	        	GROUP BY pa.album_uid) p2 WHERE p2.photo_id = f.photo_id AND f.file_primary = 1 AND f.file_error = '' AND f.file_type IN (?)
 			) b ON b.album_uid = albums.album_uid
 		SET thumb = b.file_hash WHERE ?`, media.PreviewExpr, condition)
-	case SQLite3:
+	case enum.SQLite3:
 		res = Db().Table(entity.Album{}.TableName()).
 			UpdateColumn("thumb", gorm.Expr(`(
 		SELECT f.file_hash FROM files f 
@@ -108,7 +109,7 @@ func UpdateAlbumFolderCovers(albums ...entity.Album) (err error) {
 	condition := gorm.Expr("album_type = ? AND thumb_src = ?", entity.AlbumFolder, entity.SrcAuto)
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE albums LEFT JOIN (
 		SELECT p2.photo_path, f.file_hash FROM files f, (
 			SELECT p.photo_path, max(p.id) AS photo_id FROM photos p
@@ -116,7 +117,7 @@ func UpdateAlbumFolderCovers(albums ...entity.Album) (err error) {
 			GROUP BY p.photo_path) p2 WHERE p2.photo_id = f.photo_id AND f.file_primary = 1 AND f.file_error = '' AND f.file_type IN (?)
 			) b ON b.photo_path = albums.album_path
 		SET thumb = b.file_hash WHERE ?`, media.PreviewExpr, condition)
-	case SQLite3:
+	case enum.SQLite3:
 		res = Db().Table(entity.Album{}.TableName()).UpdateColumn("thumb", gorm.Expr(`(
 		SELECT f.file_hash FROM files f,(
 			SELECT p.photo_path, max(p.id) AS photo_id FROM photos p
@@ -171,7 +172,7 @@ func UpdateAlbumMonthCovers(albums ...entity.Album) (err error) {
 	condition := gorm.Expr("album_type = ? AND thumb_src = ?", entity.AlbumMonth, entity.SrcAuto)
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE albums LEFT JOIN (
 		SELECT p2.photo_year, p2.photo_month, f.file_hash FROM files f, (
 			SELECT p.photo_year, p.photo_month, max(p.id) AS photo_id FROM photos p
@@ -179,7 +180,7 @@ func UpdateAlbumMonthCovers(albums ...entity.Album) (err error) {
 			GROUP BY p.photo_year, p.photo_month) p2 WHERE p2.photo_id = f.photo_id AND f.file_primary = 1 AND f.file_error = '' AND f.file_type IN (?)
 			) b ON b.photo_year = albums.album_year AND b.photo_month = albums.album_month
 		SET thumb = b.file_hash WHERE ?`, media.PreviewExpr, condition)
-	case SQLite3:
+	case enum.SQLite3:
 		res = Db().Table(entity.Album{}.TableName()).UpdateColumn("thumb", gorm.Expr(`(
 		SELECT f.file_hash FROM files f,(
 			SELECT p.photo_year, p.photo_month, max(p.id) AS photo_id FROM photos p
@@ -322,7 +323,7 @@ func refreshFolderAlbumCover(album entity.Album) error {
 	}
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res := Db().Exec(`UPDATE albums LEFT JOIN (
 		SELECT p2.photo_path, f.file_hash FROM files f, (
 			SELECT p.photo_path, max(p.id) AS photo_id FROM photos p
@@ -338,7 +339,7 @@ func refreshFolderAlbumCover(album entity.Album) error {
 		)
 
 		return res.Error
-	case SQLite3:
+	case enum.SQLite3:
 		res := Db().Table(entity.Album{}.TableName()).
 			Where("album_uid = ? AND album_type = ? AND thumb_src = ?", album.AlbumUID, entity.AlbumFolder, entity.SrcAuto).
 			UpdateColumn("thumb", gorm.Expr(`(
@@ -366,7 +367,7 @@ func refreshMonthAlbumCover(album entity.Album) error {
 	}
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res := Db().Exec(`UPDATE albums LEFT JOIN (
 		SELECT p2.photo_year, p2.photo_month, f.file_hash FROM files f, (
 			SELECT p.photo_year, p.photo_month, max(p.id) AS photo_id FROM photos p
@@ -383,7 +384,7 @@ func refreshMonthAlbumCover(album entity.Album) error {
 		)
 
 		return res.Error
-	case SQLite3:
+	case enum.SQLite3:
 		res := Db().Table(entity.Album{}.TableName()).
 			Where("album_uid = ? AND album_type = ? AND thumb_src = ?", album.AlbumUID, entity.AlbumMonth, entity.SrcAuto).
 			UpdateColumn("thumb", gorm.Expr(`(
@@ -416,7 +417,7 @@ func UpdateLabelCovers() (err error) {
 	condition := gorm.Expr("thumb_src = ?", entity.SrcAuto)
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE labels LEFT JOIN (
 		SELECT p2.label_id, f.file_hash FROM files f, (
 			SELECT pl.label_id as label_id, max(p.id) AS photo_id FROM photos p
@@ -432,7 +433,7 @@ func UpdateLabelCovers() (err error) {
 			) p2 WHERE p2.photo_id = f.photo_id AND f.file_primary = 1 AND f.file_error = '' AND f.file_type IN (?) AND f.file_missing = 0
 		) b ON b.label_id = labels.id
 		SET thumb = b.file_hash WHERE ?`, media.PreviewExpr, condition)
-	case SQLite3:
+	case enum.SQLite3:
 		res = Db().Table(entity.Label{}.TableName()).UpdateColumn("thumb", gorm.Expr(`(
 		SELECT f.file_hash FROM files f 
 			JOIN photos_labels pl ON pl.label_id = labels.id AND pl.photo_id = f.photo_id AND pl.uncertainty < 100
@@ -494,7 +495,7 @@ func UpdateSubjectCovers(public bool) (err error) {
 
 	// Compose SQL update query.
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		res = Db().Exec(`UPDATE subjects LEFT JOIN (
     	SELECT m.subj_uid, m.q, MAX(m.thumb) AS marker_thumb
     		FROM markers m
@@ -508,7 +509,7 @@ func UpdateSubjectCovers(public bool) (err error) {
 			photosJoin,
 			condition,
 		)
-	case SQLite3:
+	case enum.SQLite3:
 		// from := gorm.Expr(fmt.Sprintf("%s m WHERE m.subj_uid = %s.subj_uid ", markerTable, subjTable))
 		res = Db().Table(entity.Subject{}.TableName()).UpdateColumn("thumb",
 			gorm.Expr(`(
diff --git a/internal/entity/query/file_selection.go b/internal/entity/query/file_selection.go
index 54bd8d7ab..43adefc9f 100644
--- a/internal/entity/query/file_selection.go
+++ b/internal/entity/query/file_selection.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 
 	"github.com/photoprism/photoprism/internal/entity"
@@ -98,9 +99,9 @@ func SelectedFiles(frm form.Selection, o FileSelection) (results entity.Files, e
 
 	var concat string
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		concat = "CONCAT(a.path, '/%')"
-	case SQLite3:
+	case enum.SQLite3:
 		concat = "a.path || '/%'"
 	default:
 		return results, fmt.Errorf("unknown sql dialect: %s", DbDialect())
diff --git a/internal/entity/query/folders.go b/internal/entity/query/folders.go
index 5a2ec3dcb..7f9f31a43 100644
--- a/internal/entity/query/folders.go
+++ b/internal/entity/query/folders.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/entity"
 	"github.com/photoprism/photoprism/internal/mutex"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/media"
 )
@@ -75,7 +76,7 @@ func UpdateFolderDates() error {
 	defer mutex.Index.Unlock()
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		return UnscopedDb().Exec(`UPDATE folders
 		INNER JOIN
 			(SELECT photo_path, MAX(taken_at_local) AS taken_max
diff --git a/internal/entity/query/photo_selection.go b/internal/entity/query/photo_selection.go
index b282dec3d..746b179a7 100644
--- a/internal/entity/query/photo_selection.go
+++ b/internal/entity/query/photo_selection.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/entity"
 	"github.com/photoprism/photoprism/internal/form"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 // SelectedPhotos finds photos based on the given selection form, e.g. for adding them to an album.
@@ -24,9 +25,9 @@ func SelectedPhotos(frm form.Selection) (results entity.Photos, err error) {
 	var concat string
 
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		concat = "CONCAT(a.path, '/%')"
-	case SQLite3:
+	case enum.SQLite3:
 		concat = "a.path || '/%'"
 	default:
 		return results, fmt.Errorf("unknown sql dialect: %s", DbDialect())
diff --git a/internal/entity/query/query.go b/internal/entity/query/query.go
index d59f7dda5..ccc72af67 100644
--- a/internal/entity/query/query.go
+++ b/internal/entity/query/query.go
@@ -29,16 +29,11 @@ import (
 
 	"github.com/photoprism/photoprism/internal/entity"
 	"github.com/photoprism/photoprism/internal/event"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 var log = event.Log
 
-// Supported database dialect identifiers.
-const (
-	MySQL   = "mysql"
-	SQLite3 = "sqlite3"
-)
-
 // Cols represents a list of database columns.
 type Cols []string
 
@@ -79,7 +74,7 @@ func DbDialect() string {
 // BatchSize returns the maximum query parameter number based on the current sql database dialect.
 func BatchSize() int {
 	switch DbDialect() {
-	case SQLite3:
+	case enum.SQLite3:
 		return 333
 	default:
 		return 1000
diff --git a/internal/entity/search/conditions.go b/internal/entity/search/conditions.go
index e4db13ab1..7530bfa9e 100644
--- a/internal/entity/search/conditions.go
+++ b/internal/entity/search/conditions.go
@@ -14,7 +14,7 @@ import (
 // expressions. It strips operators that we don't expect to persist in the
 // statement and lets callers provide their own surrounding wildcards.
 func Like(s string) string {
-	return strings.Trim(clean.SqlString(s), " |&*%")
+	return strings.Trim(clean.SQLString(s, Db().Dialect().GetName()), " |&*%")
 }
 
 // LikeAny builds OR-chained LIKE predicates for a text column. The input string
diff --git a/internal/entity/search/conditions_test.go b/internal/entity/search/conditions_test.go
index c387ec138..c61dec7e3 100644
--- a/internal/entity/search/conditions_test.go
+++ b/internal/entity/search/conditions_test.go
@@ -8,6 +8,7 @@ import (
 	"github.com/photoprism/photoprism/internal/entity"
 
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/txt"
 )
 
@@ -16,8 +17,11 @@ func TestLike(t *testing.T) {
 		assert.Equal(t, "", Like(""))
 	})
 	t.Run("Special", func(t *testing.T) {
-		s := " ' \" \t \n %_''"
-		exp := "'' \"\"   %_''''"
+		s := " ' \" \t \n %_''\\"
+		exp := "'' \"   %_''''\\"
+		if entity.DbDialect() == enum.MySQL {
+			exp = "'' \"   %_''''\\\\"
+		}
 		result := Like(s)
 		t.Logf("String..: %s", s)
 		t.Logf("Expected: %s", exp)
@@ -135,7 +139,7 @@ func TestLikeAnyWord(t *testing.T) {
 			t.Fatalf("two where conditions expected: %#v", w)
 		} else {
 			assert.Equal(t, "k.keyword LIKE 'spoon%' OR k.keyword LIKE 'table%'", w[0])
-			assert.Equal(t, "k.keyword LIKE '\"\"us''a%'", w[1])
+			assert.Equal(t, "k.keyword LIKE '\"us''a%'", w[1])
 		}
 	})
 }
diff --git a/internal/entity/sortby/random.go b/internal/entity/sortby/random.go
index 3a79a7b98..7f47dbebe 100644
--- a/internal/entity/sortby/random.go
+++ b/internal/entity/sortby/random.go
@@ -4,21 +4,18 @@ import (
 	"github.com/jinzhu/gorm"
 	_ "github.com/jinzhu/gorm/dialects/mysql"
 	_ "github.com/jinzhu/gorm/dialects/sqlite"
-)
 
-const (
-	MySQL   = "mysql"
-	SQLite3 = "sqlite3"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 // RandomExpr returns the name of the random function depending on the SQL dialect.
 func RandomExpr(dialect gorm.Dialect) *gorm.SqlExpr {
 	switch dialect.GetName() {
-	case MySQL:
+	case enum.MySQL:
 		// A seed integer can be passed as an argument, e.g. "RAND(2342)", to generate
 		// reproducible pseudo-random values, see https://mariadb.com/kb/en/rand/.
 		return gorm.Expr("RAND()")
-	case SQLite3:
+	case enum.SQLite3:
 		// SQLite does not support specifying a seed to generate a deterministic sequence
 		// of pseudo-random values, see https://www.sqlite.org/lang_corefunc.html#random.
 		return gorm.Expr("RANDOM()")
diff --git a/internal/entity/sortby/random_test.go b/internal/entity/sortby/random_test.go
index 4f7f91f02..d127b3fd1 100644
--- a/internal/entity/sortby/random_test.go
+++ b/internal/entity/sortby/random_test.go
@@ -5,12 +5,14 @@ import (
 
 	"github.com/jinzhu/gorm"
 
+	"github.com/photoprism/photoprism/pkg/enum"
+
 	"github.com/stretchr/testify/assert"
 )
 
 func TestRandomExpr(t *testing.T) {
-	mysql, _ := gorm.GetDialect(MySQL)
-	sqlite3, _ := gorm.GetDialect(SQLite3)
+	mysql, _ := gorm.GetDialect(enum.MySQL)
+	sqlite3, _ := gorm.GetDialect(enum.SQLite3)
 
 	assert.Equal(t, gorm.Expr("RAND()"), RandomExpr(mysql))
 	assert.Equal(t, gorm.Expr("RANDOM()"), RandomExpr(sqlite3))
diff --git a/internal/entity/subject.go b/internal/entity/subject.go
index 531213ce2..46a0e4c42 100644
--- a/internal/entity/subject.go
+++ b/internal/entity/subject.go
@@ -11,6 +11,7 @@ import (
 	"github.com/photoprism/photoprism/internal/event"
 	"github.com/photoprism/photoprism/internal/form"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/rnd"
 	"github.com/photoprism/photoprism/pkg/txt"
 )
@@ -490,7 +491,7 @@ func (m *Subject) RefreshPhotos() error {
 
 	var err error
 	switch DbDialect() {
-	case MySQL:
+	case enum.MySQL:
 		update := fmt.Sprintf(`UPDATE photos p JOIN files f ON f.photo_id = p.id JOIN %s m ON m.file_uid = f.file_uid
 			SET p.checked_at = NULL WHERE m.subj_uid = ?`, Marker{}.TableName())
 		err = UnscopedDb().Exec(update, m.SubjUID).Error
diff --git a/internal/photoprism/backup/database.go b/internal/photoprism/backup/database.go
index a463d9db4..95c0ab70d 100644
--- a/internal/photoprism/backup/database.go
+++ b/internal/photoprism/backup/database.go
@@ -15,10 +15,10 @@ import (
 
 	"github.com/dustin/go-humanize/english"
 
-	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/entity"
 	"github.com/photoprism/photoprism/internal/photoprism/get"
 	"github.com/photoprism/photoprism/pkg/clean"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
@@ -73,7 +73,7 @@ func Database(backupPath, fileName string, toStdOut, force bool, retain int) (er
 	var cmd *exec.Cmd
 
 	switch c.DatabaseDriver() {
-	case config.MySQL, config.MariaDB:
+	case enum.MySQL, enum.MariaDB:
 		// Connect via Unix Domain Socket?
 		if socketName := c.DatabaseServer(); strings.HasPrefix(socketName, "/") {
 			cmd = exec.Command( // #nosec G204 database connection parameters from trusted config
@@ -112,7 +112,7 @@ func Database(backupPath, fileName string, toStdOut, force bool, retain int) (er
 				c.DatabaseName(),
 			)
 		}
-	case config.SQLite3:
+	case enum.SQLite3:
 		if !fs.FileExistsNotEmpty(c.DatabaseFile()) {
 			return fmt.Errorf("sqlite database file %s not found", clean.LogQuote(c.DatabaseFile()))
 		}
@@ -254,7 +254,7 @@ func RestoreDatabase(backupPath, fileName string, fromStdIn, force bool) (err er
 	var cmd *exec.Cmd
 
 	switch c.DatabaseDriver() {
-	case config.MySQL, config.MariaDB:
+	case enum.MySQL, enum.MariaDB:
 		// Connect via Unix Domain Socket?
 		if socketName := c.DatabaseServer(); strings.HasPrefix(socketName, "/") {
 			cmd = exec.Command( // #nosec G204 database connection parameters from config
@@ -296,7 +296,7 @@ func RestoreDatabase(backupPath, fileName string, fromStdIn, force bool) (err er
 				c.DatabaseName(),
 			)
 		}
-	case config.SQLite3:
+	case enum.SQLite3:
 		log.Infoln("restore: dropping existing sqlite database tables")
 		tables.Drop(c.Db())
 		cmd = exec.Command( // #nosec G204 sqlite restore uses configured binary and db path
diff --git a/internal/service/cluster/node/bootstrap_test.go b/internal/service/cluster/node/bootstrap_test.go
index 7816b516e..9ec7b71de 100644
--- a/internal/service/cluster/node/bootstrap_test.go
+++ b/internal/service/cluster/node/bootstrap_test.go
@@ -14,7 +14,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/service/cluster"
-	"github.com/photoprism/photoprism/pkg/dsn"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
@@ -61,7 +61,7 @@ func TestRegister_PersistSecretAndDB(t *testing.T) {
 				Secrets:     &cluster.RegisterSecrets{ClientSecret: cluster.ExampleClientSecret},
 				JWKSUrl:     jwksURL,
 				Database: cluster.RegisterDatabase{
-					Driver:   dsn.DriverMySQL,
+					Driver:   enum.MySQL,
 					Host:     "db.local",
 					Port:     3306,
 					Name:     "pp_db",
@@ -92,7 +92,7 @@ func TestRegister_PersistSecretAndDB(t *testing.T) {
 	expectedAppName = c.About()
 	expectedAppVersion = c.Version()
 	// Gate rotate=true: driver mysql and no DSN/fields.
-	c.Options().DatabaseDriver = dsn.DriverMySQL
+	c.Options().DatabaseDriver = enum.MySQL
 	c.Options().DatabaseDSN = ""
 	c.Options().DatabaseName = ""
 	c.Options().DatabaseUser = ""
@@ -105,7 +105,7 @@ func TestRegister_PersistSecretAndDB(t *testing.T) {
 	assert.Equal(t, cluster.ExampleClientSecret, c.NodeClientSecret())
 	// DSN branch should be preferred and persisted.
 	assert.Contains(t, c.Options().DatabaseDSN, "@tcp(db.local:3306)/pp_db")
-	assert.Equal(t, dsn.DriverMySQL, c.Options().DatabaseDriver)
+	assert.Equal(t, enum.MySQL, c.Options().DatabaseDriver)
 	assert.Equal(t, srv.URL+"/.well-known/jwks.json", c.JWKSUrl())
 	assert.Equal(t, "192.0.2.0/24", c.ClusterCIDR())
 }
@@ -277,7 +277,7 @@ func TestRegister_SQLite_NoDBPersist(t *testing.T) {
 
 	// NodeClientSecret should persist, but DB should remain SQLite (no DSN update).
 	assert.Equal(t, cluster.ExampleClientSecret, c.NodeClientSecret())
-	assert.Equal(t, config.SQLite3, c.DatabaseDriver())
+	assert.Equal(t, enum.SQLite3, c.DatabaseDriver())
 	assert.Equal(t, origDSN, c.Options().DatabaseDSN)
 	assert.Equal(t, srv.URL+"/.well-known/jwks.json", c.JWKSUrl())
 	assert.Equal(t, "203.0.113.0/24", c.ClusterCIDR())
diff --git a/internal/service/cluster/provisioner/credentials.go b/internal/service/cluster/provisioner/credentials.go
index b27bea3c3..741b94e6b 100644
--- a/internal/service/cluster/provisioner/credentials.go
+++ b/internal/service/cluster/provisioner/credentials.go
@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"github.com/photoprism/photoprism/internal/config"
-	"github.com/photoprism/photoprism/pkg/dsn"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 // Credentials contains the connection details returned when ensuring a node database.
@@ -35,9 +35,9 @@ func EnsureCredentials(ctx context.Context, conf *config.Config, nodeUUID, nodeN
 	driver := strings.ToLower(DatabaseDriver)
 
 	switch driver {
-	case dsn.DriverMySQL, dsn.DriverMariaDB:
+	case enum.MySQL, enum.MariaDB:
 		// ok
-	case dsn.DriverSQLite3, dsn.DriverPostgres:
+	case enum.SQLite3, enum.Postgres:
 		return out, false, errors.New("database must be MySQL/MariaDB for auto-provisioning")
 	default:
 		// Driver is configured externally for the provisioner (decoupled from app config).
diff --git a/internal/service/cluster/provisioner/naming.go b/internal/service/cluster/provisioner/naming.go
index 0a486522f..c802d30ee 100644
--- a/internal/service/cluster/provisioner/naming.go
+++ b/internal/service/cluster/provisioner/naming.go
@@ -10,6 +10,7 @@ import (
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/service/cluster"
 	"github.com/photoprism/photoprism/pkg/dsn"
+	"github.com/photoprism/photoprism/pkg/enum"
 	"github.com/photoprism/photoprism/pkg/rnd"
 )
 
@@ -64,9 +65,9 @@ func GenerateCredentials(conf *config.Config, nodeUUID, nodeName string) (dbName
 func BuildDSN(driver, host string, port int, user, pass, name string) string {
 	d := strings.ToLower(driver)
 	switch d {
-	case dsn.DriverMySQL, dsn.DriverMariaDB:
+	case enum.MySQL, enum.MariaDB:
 		return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?%s",
-			user, pass, host, port, name, dsn.Params[dsn.DriverMySQL],
+			user, pass, host, port, name, dsn.Params[enum.MySQL],
 		)
 	default:
 		log.Warnf("provisioner: unsupported driver %q, falling back to mysql DSN format", driver)
diff --git a/internal/service/cluster/provisioner/naming_test.go b/internal/service/cluster/provisioner/naming_test.go
index 7d18c5291..760fbde66 100644
--- a/internal/service/cluster/provisioner/naming_test.go
+++ b/internal/service/cluster/provisioner/naming_test.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/service/cluster"
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 func TestGenerateCredentials_StabilityAndBudgets(t *testing.T) {
@@ -103,7 +104,7 @@ func TestEnsureCredentials_SqliteRejected(t *testing.T) {
 	ctx := context.Background()
 	c := config.NewConfig(config.CliTestContext())
 	origDriver := DatabaseDriver
-	DatabaseDriver = config.SQLite3
+	DatabaseDriver = enum.SQLite3
 	t.Cleanup(func() { DatabaseDriver = origDriver })
 
 	_, _, err := EnsureCredentials(ctx, c, "11111111-1111-4111-8111-111111111111", "pp-node-01", false)
diff --git a/pkg/clean/sql.go b/pkg/clean/sql.go
index ba41876a6..1a88f3fe2 100644
--- a/pkg/clean/sql.go
+++ b/pkg/clean/sql.go
@@ -1,24 +1,35 @@
 package clean
 
-// SqlSpecial checks if the byte must be escaped/omitted in SQL.
-func SqlSpecial(b byte) (special bool, omit bool) {
+import "github.com/photoprism/photoprism/pkg/enum"
+
+// SQLSpecial checks if the byte must be escaped/omitted in SQL.
+func SQLSpecial(b byte, dialect string) (special bool, omit bool) {
 	if b < 32 {
 		return true, true
 	}
 
-	switch b {
-	case '"', '\'', '\\':
-		return true, false
-	default:
-		return false, false
+	if dialect == enum.MySQL {
+		switch b {
+		case '\'', '\\':
+			return true, false
+		default:
+			return false, false
+		}
+	} else {
+		switch b {
+		case '\'':
+			return true, false
+		default:
+			return false, false
+		}
 	}
 }
 
-// SqlString escapes a string for use in an SQL query.
-func SqlString(s string) string {
+// SQLString escapes a string for use in an SQL query.
+func SQLString(s string, dialect string) string {
 	var i int
 	for i = 0; i < len(s); i++ {
-		if found, _ := SqlSpecial(s[i]); found {
+		if found, _ := SQLSpecial(s[i], dialect); found {
 			break
 		}
 	}
@@ -35,7 +46,7 @@ func SqlString(s string) string {
 	j := i
 
 	for ; i < len(s); i++ {
-		if special, omit := SqlSpecial(s[i]); omit {
+		if special, omit := SQLSpecial(s[i], dialect); omit {
 			// Omit control characters.
 			continue
 		} else if special {
diff --git a/pkg/clean/sql_test.go b/pkg/clean/sql_test.go
index 5da499d28..dbbb8ff5e 100644
--- a/pkg/clean/sql_test.go
+++ b/pkg/clean/sql_test.go
@@ -4,81 +4,210 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
-func TestSqlSpecial(t *testing.T) {
-	t.Run("Special", func(t *testing.T) {
-		if s, o := SqlSpecial(1); !s {
+func TestSQLSpecial(t *testing.T) {
+	t.Run("Special MySQL", func(t *testing.T) {
+		if s, o := SQLSpecial(1, enum.MySQL); !s {
 			t.Error("char is special")
 		} else if !o {
 			t.Error("\" must be omitted")
 		}
 
-		if s, o := SqlSpecial(31); !s {
+		if s, o := SQLSpecial(31, enum.MySQL); !s {
 			t.Error("char is special")
 		} else if !o {
 			t.Error("\" must be omitted")
 		}
 
-		if s, o := SqlSpecial('\\'); !s {
+		if s, o := SQLSpecial('\\', enum.MySQL); !s {
 			t.Error("\\ is special")
 		} else if o {
 			t.Error("\\ must not be omitted")
 		}
 
-		if s, o := SqlSpecial('\''); !s {
+		if s, o := SQLSpecial('\'', enum.MySQL); !s {
 			t.Error("' is special")
 		} else if o {
 			t.Error("' must not be omitted")
 		}
+	})
+	t.Run("Special SQLite", func(t *testing.T) {
+		if s, o := SQLSpecial(1, enum.SQLite3); !s {
+			t.Error("char is special")
+		} else if !o {
+			t.Error("\" must be omitted")
+		}
 
-		if s, o := SqlSpecial('"'); !s {
-			t.Error("\" is special")
+		if s, o := SQLSpecial(31, enum.SQLite3); !s {
+			t.Error("char is special")
+		} else if !o {
+			t.Error("\" must be omitted")
+		}
+
+		if s, o := SQLSpecial('\'', enum.SQLite3); !s {
+			t.Error("' is special")
 		} else if o {
-			t.Error("\" must not be omitted")
+			t.Error("' must not be omitted")
 		}
 	})
-	t.Run("NotSpecial", func(t *testing.T) {
-		if s, o := SqlSpecial(32); s {
+	t.Run("Special Postgres", func(t *testing.T) {
+		if s, o := SQLSpecial(1, enum.Postgres); !s {
+			t.Error("char is special")
+		} else if !o {
+			t.Error("\" must be omitted")
+		}
+
+		if s, o := SQLSpecial(31, enum.Postgres); !s {
+			t.Error("char is special")
+		} else if !o {
+			t.Error("\" must be omitted")
+		}
+
+		if s, o := SQLSpecial('\'', enum.Postgres); !s {
+			t.Error("' is special")
+		} else if o {
+			t.Error("' must not be omitted")
+		}
+	})
+
+	t.Run("NotSpecial MySQL", func(t *testing.T) {
+		if s, o := SQLSpecial(32, enum.MySQL); s {
 			t.Error("space is not special")
 		} else if o {
 			t.Error("space must not be omitted")
 		}
 
-		if s, o := SqlSpecial('A'); s {
+		if s, o := SQLSpecial('A', enum.MySQL); s {
 			t.Error("A is not special")
 		} else if o {
 			t.Error("A must not be omitted")
 		}
 
-		if s, o := SqlSpecial('a'); s {
+		if s, o := SQLSpecial('a', enum.MySQL); s {
 			t.Error("a is not special")
 		} else if o {
 			t.Error("a must not be omitted")
 		}
 
-		if s, o := SqlSpecial('_'); s {
+		if s, o := SQLSpecial('_', enum.MySQL); s {
 			t.Error("_ is not special")
 		} else if o {
 			t.Error("_ must not be omitted")
 		}
+
+		if s, o := SQLSpecial('"', enum.MySQL); s {
+			t.Error("\" is not special")
+		} else if o {
+			t.Error("\" must not be omitted")
+		}
+	})
+	t.Run("NotSpecial SQLite", func(t *testing.T) {
+		if s, o := SQLSpecial(32, enum.SQLite3); s {
+			t.Error("space is not special")
+		} else if o {
+			t.Error("space must not be omitted")
+		}
+
+		if s, o := SQLSpecial('A', enum.SQLite3); s {
+			t.Error("A is not special")
+		} else if o {
+			t.Error("A must not be omitted")
+		}
+
+		if s, o := SQLSpecial('a', enum.SQLite3); s {
+			t.Error("a is not special")
+		} else if o {
+			t.Error("a must not be omitted")
+		}
+
+		if s, o := SQLSpecial('_', enum.SQLite3); s {
+			t.Error("_ is not special")
+		} else if o {
+			t.Error("_ must not be omitted")
+		}
+
+		if s, o := SQLSpecial('"', enum.SQLite3); s {
+			t.Error("\" is not special")
+		} else if o {
+			t.Error("\" must not be omitted")
+		}
+
+		if s, o := SQLSpecial('\\', enum.SQLite3); s {
+			t.Error("\\ is not special")
+		} else if o {
+			t.Error("\\ must not be omitted")
+		}
+	})
+	t.Run("NotSpecial Postgres", func(t *testing.T) {
+		if s, o := SQLSpecial(32, enum.Postgres); s {
+			t.Error("space is not special")
+		} else if o {
+			t.Error("space must not be omitted")
+		}
+
+		if s, o := SQLSpecial('A', enum.Postgres); s {
+			t.Error("A is not special")
+		} else if o {
+			t.Error("A must not be omitted")
+		}
+
+		if s, o := SQLSpecial('a', enum.Postgres); s {
+			t.Error("a is not special")
+		} else if o {
+			t.Error("a must not be omitted")
+		}
+
+		if s, o := SQLSpecial('_', enum.Postgres); s {
+			t.Error("_ is not special")
+		} else if o {
+			t.Error("_ must not be omitted")
+		}
+
+		if s, o := SQLSpecial('"', enum.Postgres); s {
+			t.Error("\" is not special")
+		} else if o {
+			t.Error("\" must not be omitted")
+		}
+
+		if s, o := SQLSpecial('\\', enum.Postgres); s {
+			t.Error("\\ is not special")
+		} else if o {
+			t.Error("\\ must not be omitted")
+		}
 	})
 }
 
 func TestSqlString(t *testing.T) {
 	t.Run("Empty", func(t *testing.T) {
-		assert.Equal(t, "", SqlString(""))
+		assert.Equal(t, "", SQLString("", enum.MySQL))
+		assert.Equal(t, "", SQLString("", enum.SQLite3))
+		assert.Equal(t, "", SQLString("", enum.Postgres))
 	})
 	t.Run("Special", func(t *testing.T) {
-		s := "' \" \t \n %_''"
-		exp := "'' \"\"   %_''''"
-		result := SqlString(s)
+		s := "' \" \t \n %_''\\"
+		exp := "'' \"   %_''''\\\\"
+		result := SQLString(s, enum.MySQL)
+		t.Logf("String..: %s", s)
+		t.Logf("Expected: %s", exp)
+		t.Logf("Result..: %s", result)
+		assert.Equal(t, exp, result)
+		exp = "'' \"   %_''''\\"
+		result = SQLString(s, enum.SQLite3)
+		t.Logf("String..: %s", s)
+		t.Logf("Expected: %s", exp)
+		t.Logf("Result..: %s", result)
+		assert.Equal(t, exp, result)
+		exp = "'' \"   %_''''\\"
+		result = SQLString(s, enum.Postgres)
 		t.Logf("String..: %s", s)
 		t.Logf("Expected: %s", exp)
 		t.Logf("Result..: %s", result)
 		assert.Equal(t, exp, result)
 	})
 	t.Run("Alnum", func(t *testing.T) {
-		assert.Equal(t, "123ABCabc", SqlString("123ABCabc"))
+		assert.Equal(t, "123ABCabc", SQLString("123ABCabc", enum.MySQL))
 	})
 }
diff --git a/pkg/dsn/driver.go b/pkg/dsn/driver.go
index 70c0bedac..8c4f20540 100644
--- a/pkg/dsn/driver.go
+++ b/pkg/dsn/driver.go
@@ -1,23 +1,11 @@
 package dsn
 
-// SQL database drivers.
-const (
-	DriverMySQL    = "mysql"
-	DriverMariaDB  = "mariadb"
-	DriverPostgres = "postgres"
-	DriverSQLite3  = "sqlite3"
-)
-
-// SQLite default DSNs.
-const (
-	SQLiteTestDB = ".test.db"
-	SQLiteMemory = ":memory:"
-)
+import "github.com/photoprism/photoprism/pkg/enum"
 
 // Params maps required DSN parameters by driver type.
 var Params = Values{
-	DriverMySQL:    "charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
-	DriverMariaDB:  "charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
-	DriverPostgres: "sslmode=disable TimeZone=UTC",
-	DriverSQLite3:  "_busy_timeout=5000",
+	enum.MySQL:    "charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
+	enum.MariaDB:  "charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
+	enum.Postgres: "sslmode=disable TimeZone=UTC",
+	enum.SQLite3:  "_busy_timeout=5000",
 }
diff --git a/pkg/dsn/dsn.go b/pkg/dsn/dsn.go
index fe4aa9271..740105d99 100644
--- a/pkg/dsn/dsn.go
+++ b/pkg/dsn/dsn.go
@@ -31,6 +31,8 @@ import (
 	"strconv"
 	"strings"
 	"unicode"
+
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 // dsnPattern is a regular expression matching a database DSN string.
@@ -75,7 +77,7 @@ func (d *DSN) MaskPassword() (s string) {
 	}
 
 	// Mask password in PostgreSQL-style DSN.
-	if d.Driver == DriverPostgres || strings.Contains(s, "password=") {
+	if d.Driver == enum.Postgres || strings.Contains(s, "password=") {
 		return dsnPostgresPasswordPattern.ReplaceAllStringFunc(s, func(segment string) string {
 			matches := dsnPostgresPasswordPattern.FindStringSubmatch(segment)
 			if len(matches) != 3 {
@@ -107,7 +109,7 @@ func (d *DSN) MaskPassword() (s string) {
 
 // Host the database server host.
 func (d *DSN) Host() string {
-	if d.Driver == DriverSQLite3 {
+	if d.Driver == enum.SQLite3 {
 		return ""
 	}
 
@@ -117,16 +119,17 @@ func (d *DSN) Host() string {
 
 // Port the database server port.
 func (d *DSN) Port() int {
-	if d.Driver == DriverSQLite3 {
+	switch d.Driver {
+	case enum.SQLite3:
 		return 0
 	}
 
 	defaultPort := 0
 
 	switch d.Driver {
-	case DriverMySQL, DriverMariaDB:
+	case enum.MySQL, enum.MariaDB:
 		defaultPort = 3306
-	case DriverPostgres:
+	case enum.Postgres:
 		defaultPort = 5432
 	}
 
@@ -249,7 +252,7 @@ func (d *DSN) parsePostgres() bool {
 		}
 	}
 
-	d.Driver = DriverPostgres
+	d.Driver = enum.Postgres
 	d.User = values["user"]
 	d.Password = values["password"]
 	d.Name = name
@@ -371,13 +374,13 @@ func (d *DSN) detectDriver() {
 
 	switch driver {
 	case "postgres", "postgresql":
-		d.Driver = DriverPostgres
+		d.Driver = enum.Postgres
 		return
 	case "mysql", "mariadb":
-		d.Driver = DriverMySQL
+		d.Driver = enum.MySQL
 		return
 	case "sqlite", "sqlite3", "file":
-		d.Driver = DriverSQLite3
+		d.Driver = enum.SQLite3
 		return
 	}
 
@@ -389,26 +392,26 @@ func (d *DSN) detectDriver() {
 	lower := strings.ToLower(d.DSN)
 
 	if strings.Contains(lower, "postgres://") || strings.Contains(lower, "postgresql://") {
-		d.Driver = DriverPostgres
+		d.Driver = enum.Postgres
 		return
 	}
 
 	if d.Net == "tcp" || d.Net == "unix" || strings.Contains(lower, "@tcp(") || strings.Contains(lower, "@unix(") {
-		d.Driver = DriverMySQL
+		d.Driver = enum.MySQL
 		return
 	}
 
 	if strings.HasPrefix(lower, "file:") || strings.HasSuffix(lower, ".db") || strings.HasSuffix(strings.ToLower(d.Name), ".db") {
-		d.Driver = DriverSQLite3
+		d.Driver = enum.SQLite3
 		return
 	}
 
 	if strings.Contains(lower, " host=") && strings.Contains(lower, " dbname=") {
-		d.Driver = DriverPostgres
+		d.Driver = enum.Postgres
 		return
 	}
 
 	if d.Server != "" && (strings.Contains(d.Server, ":") || d.Net != "") && d.Driver == "" {
-		d.Driver = DriverMySQL
+		d.Driver = enum.MySQL
 	}
 }
diff --git a/pkg/dsn/dsn_test.go b/pkg/dsn/dsn_test.go
index 52af01054..ae8fa0af6 100644
--- a/pkg/dsn/dsn_test.go
+++ b/pkg/dsn/dsn_test.go
@@ -4,6 +4,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 func TestDSN_HostAndPort(t *testing.T) {
@@ -95,7 +97,7 @@ func TestDSN_ParsePostgres(t *testing.T) {
 			in:   "user=alice password=s3cr3t dbname=app",
 			want: DSN{
 				DSN:      "user=alice password=s3cr3t dbname=app",
-				Driver:   DriverPostgres,
+				Driver:   enum.Postgres,
 				User:     "alice",
 				Password: "s3cr3t",
 				Name:     "app",
@@ -107,7 +109,7 @@ func TestDSN_ParsePostgres(t *testing.T) {
 			in:   "user=alice password=s3cr3t dbname=app host=db.internal port=5432 connect_timeout=5 sslmode=require",
 			want: DSN{
 				DSN:      "user=alice password=s3cr3t dbname=app host=db.internal port=5432 connect_timeout=5 sslmode=require",
-				Driver:   DriverPostgres,
+				Driver:   enum.Postgres,
 				User:     "alice",
 				Password: "s3cr3t",
 				Server:   "db.internal:5432",
@@ -121,7 +123,7 @@ func TestDSN_ParsePostgres(t *testing.T) {
 			in:   `user="alice" password="s ec ret" dbname="app" host=db.internal`,
 			want: DSN{
 				DSN:      `user="alice" password="s ec ret" dbname="app" host=db.internal`,
-				Driver:   DriverPostgres,
+				Driver:   enum.Postgres,
 				User:     "alice",
 				Password: "s ec ret",
 				Server:   "db.internal",
diff --git a/pkg/dsn/parse_test.go b/pkg/dsn/parse_test.go
index 26b28feef..fd634d57f 100644
--- a/pkg/dsn/parse_test.go
+++ b/pkg/dsn/parse_test.go
@@ -4,6 +4,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/photoprism/photoprism/pkg/enum"
 )
 
 func TestParse(t *testing.T) {
@@ -17,7 +19,7 @@ func TestParse(t *testing.T) {
 			in:   "user:secret@tcp(localhost:3306)/photoprism?charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
 			want: DSN{
 				DSN:      "user:secret@tcp(localhost:3306)/photoprism?charset=utf8mb4,utf8&collation=utf8mb4_unicode_ci&parseTime=true",
-				Driver:   DriverMySQL,
+				Driver:   enum.MySQL,
 				User:     "user",
 				Password: "secret",
 				Net:      "tcp",
@@ -31,7 +33,7 @@ func TestParse(t *testing.T) {
 			in:   "mysql://user:secret@localhost:3306/photoprism?parseTime=true",
 			want: DSN{
 				DSN:      "mysql://user:secret@localhost:3306/photoprism?parseTime=true",
-				Driver:   DriverMySQL,
+				Driver:   enum.MySQL,
 				User:     "user",
 				Password: "secret",
 				Server:   "localhost:3306",
@@ -44,7 +46,7 @@ func TestParse(t *testing.T) {
 			in:   "user:secret@unix(/var/run/mysql.sock)/photoprism",
 			want: DSN{
 				DSN:      "user:secret@unix(/var/run/mysql.sock)/photoprism",
-				Driver:   DriverMySQL,
+				Driver:   enum.MySQL,
 				User:     "user",
 				Password: "secret",
 				Net:      "unix",
@@ -57,7 +59,7 @@ func TestParse(t *testing.T) {
 			in:   "file:/data/index.db?_busy_timeout=5000",
 			want: DSN{
 				DSN:    "file:/data/index.db?_busy_timeout=5000",
-				Driver: DriverSQLite3,
+				Driver: enum.SQLite3,
 				Server: "file:/data",
 				Name:   "index.db",
 				Params: "_busy_timeout=5000",
@@ -68,7 +70,7 @@ func TestParse(t *testing.T) {
 			in:   "/index.db?_busy_timeout=5000",
 			want: DSN{
 				DSN:    "/index.db?_busy_timeout=5000",
-				Driver: DriverSQLite3,
+				Driver: enum.SQLite3,
 				Server: "",
 				Name:   "index.db",
 				Params: "_busy_timeout=5000",
@@ -79,7 +81,7 @@ func TestParse(t *testing.T) {
 			in:   "user=alice password=s3cr3t dbname=app host=db.internal port=5432 connect_timeout=5 sslmode=require",
 			want: DSN{
 				DSN:      "user=alice password=s3cr3t dbname=app host=db.internal port=5432 connect_timeout=5 sslmode=require",
-				Driver:   DriverPostgres,
+				Driver:   enum.Postgres,
 				User:     "alice",
 				Password: "s3cr3t",
 				Server:   "db.internal:5432",
diff --git a/pkg/enum/enum.go b/pkg/enum/enum.go
index d0b20a92c..1899cec61 100644
--- a/pkg/enum/enum.go
+++ b/pkg/enum/enum.go
@@ -24,3 +24,8 @@ Additional information can be found in our Developer Guide:
 <https://docs.photoprism.app/developer-guide/>
 */
 package enum
+
+// Automatically choose the appropriate "thing"
+const (
+	Auto = "auto"
+)
diff --git a/pkg/enum/sql.go b/pkg/enum/sql.go
new file mode 100644
index 000000000..8b261bbad
--- /dev/null
+++ b/pkg/enum/sql.go
@@ -0,0 +1,19 @@
+package enum
+
+// Supported database(s)
+const (
+	MySQL   = "mysql"
+	MariaDB = "mariadb"
+	SQLite3 = "sqlite3"
+)
+
+// Future database(s)
+const (
+	Postgres = "postgres"
+)
+
+// Test database(s)
+const (
+	SQLiteTestDB    = ".test.db"
+	SQLiteMemoryDSN = ":memory:?cache=shared"
+)