presto-base-jdbc/src/main/java/io/prestosql/plugin/jdbc/JdbcMetadata.java/JdbcMetadata/schemaExists
class JdbcMetadata:    @Override
    public boolean schemaExists(ConnectorSession session, String schemaName)
    {
        return jdbcClient.schemaExists(JdbcIdentity.from(session), schemaName);
    }