## Migration from another search provider

Please see [MIGRATION.md](MIGRATION.md).

## Data Store

Currently, Fess supports crawling the following [storage locations and APIs](https://fess.codelibs.org/15.0/admin/dataconfig-guide.html):

// https://github.com/gradle/gradle-private/issues/4528
// Trigger ReadyForNightly and ReadyForRelease for provider-api-migration/public-api-changes branch
// TODO: remove this after the branch is merged
const val PROVIDER_API_MIGRATION_BRANCH = "provider-api-migration/public-api-changes"
const val BOT_DAILY_UPGRADLE_WRAPPER_BRANCH = "devprod/upgrade-to-latest-wrapper"

 *
 * <p>Key features include:</p>
 * <ul>
 *   <li>Project upgrade capabilities</li>
 *   <li>Dependency version management</li>
 *   <li>Configuration migration</li>
 *   <li>Interactive upgrade workflows</li>
 * </ul>
 *
 * @see org.apache.maven.api.cli.Tools#MVNUP_CMD
 * @see org.apache.maven.api.cli.Tools#MVNUP_NAME
 * @since 4.0.0
 */

		// Preserve older credential if we do not have
		// root credentials set via environment variable.
		globalActiveCred = cfg.Credential
	}

	// Init compression config. For future migration, Compression config needs to be copied over from previous version.
	switch cfg.Version {
	case "29":
		// V29 -> V30
		cfg.Compression.Enabled = false

Here we create the tables on an application startup event.

For production you would probably use a migration script that runs before you start your app. 🤓

/// tip

SQLModel will have migration utilities wrapping Alembic, but for now, you can use <a href="https://alembic.sqlalchemy.org/en/latest/" class="external-link" target="_blank">Alembic</a> directly.

///

	}
	if err == nil {
		b.defaultTimestamps()
	}

	// If bucket metadata is missing look for legacy files,
	// since we only ever had b.Created as non-zero when
	// migration was complete in 2020-May release. So this
	// a check to avoid migrating for buckets that already
	// have this field set.
	if b.Created.IsZero() {
		configs, err := b.getAllLegacyConfigs(ctx, objectAPI)
		if err != nil {
			return b, err
		}

		gorm.Model
		Name string
	}

	if err := DB.Migrator().RenameTable(&TableStruct{}, &NewTableStruct{}); err != nil {
		t.Fatalf("Failed to rename table, got error %v", err)
	}

	if !DB.Migrator().HasTable("new_table_structs") {
		t.Fatal("should found renamed table")
	}

	DB.Migrator().DropTable("new_table_structs")

	if DB.Migrator().HasTable(&NewTableStruct{}) {

		t.Fatalf("expected value false, got %t", ok)
	}

	formats[2].Erasure.This = ""
	if ok := formatErasureV3ThisEmpty(formats); !ok {
		t.Fatalf("expected value true, got %t", ok)
	}
}

// Tests xl format migration.
func TestFormatErasureMigrate(t *testing.T) {
	// Get test root.
	rootPath := t.TempDir()

	m := &formatErasureV1{}
	m.Format = formatBackendErasure
	m.Version = formatMetaVersionV1

	NewValuePool           FieldNewValuePool

	// In some db (e.g. MySQL), Unique and UniqueIndex are indistinguishable.
	// When a column has a (not Mul) UniqueIndex, Migrator always reports its gorm.ColumnType is Unique.
	// It causes field unnecessarily migration.
	// Therefore, we need to record the UniqueIndex on this column (exclude Mul UniqueIndex) for MigrateColumnUnique.
	UniqueIndex string
}

	if err := json.Unmarshal(b, format); err != nil {
		return "", err
	}
	return format.Erasure.Version, nil
}

// Migrates all previous versions to latest version of `format.json`,
// this code calls migration in sequence, such as V1 is migrated to V2
// first before it V2 migrates to V3.n
func formatErasureMigrate(export string) ([]byte, fs.FileInfo, error) {
	formatPath := pathJoin(export, minioMetaBucket, formatConfigFile)