public static Optional<JdbcDialect> getCustomDialect(String dialectImpl) {
        JdbcDialect jdbcDialect = CUSTOM_DIALECTS.get(dialectImpl);
        if (jdbcDialect != null) {
            return Optional.of(jdbcDialect);
        }
        return Optional.empty();
    }
Fetch the JdbcDialect class corresponding to a given database url.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/jdbc/src/main/java/org/apache/inlong/sort/jdbc/table/JdbcDialects.java