presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/file/FileHiveMetastore.java/FileHiveMetastore/getDatabase
class FileHiveMetastore:    @Override
    public synchronized Optional<Database> getDatabase(String databaseName)
    {
        requireNonNull(databaseName, "databaseName is null");

        Path databaseMetadataDirectory = getDatabaseMetadataDirectory(databaseName);
        return readSchemaFile("database", databaseMetadataDirectory, databaseCodec)
                .map(databaseMetadata -> databaseMetadata.toDatabase(databaseName, databaseMetadataDirectory.toString()));
    }