presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoDatabaseMetaData.java/PrestoDatabaseMetaData/getSchemas
class PrestoDatabaseMetaData:    @Override
    public ResultSet getSchemas(String catalog, String schemaPattern)
            throws SQLException
    {
        StringBuilder query = new StringBuilder("" +
                "SELECT TABLE_SCHEM, TABLE_CATALOG\n" +
                "FROM system.jdbc.schemas");

        List<String> filters = new ArrayList<>();
        emptyStringEqualsFilter(filters, "TABLE_CATALOG", catalog);
        optionalStringLikeFilter(filters, "TABLE_SCHEM", schemaPattern);
        buildFilters(query, filters);

        query.append("\nORDER BY TABLE_CATALOG, TABLE_SCHEM");

        return select(query.toString());
    }