How to Resolve Apache Calcite SqlParser Failures with Specific PostgreSQL Keywords

What are the reasons behind the Apache Calcite SqlParser failing with certain PostgreSQL keywords, and how can this issue be resolved?

// Example SQL that may cause parsing issues
SELECT * FROM table_name USING keyword;

The Apache Calcite SqlParser may encounter issues parsing SQL statements that include certain PostgreSQL keywords due to conflicts with reserved keywords or syntax parsing limitations. Understanding these issues can help you adjust your SQL queries accordingly.

SELECT * FROM "table" USING "keyword"; // Refactored SQL to avoid parsing issues

Causes

• PostgreSQL has a set of reserved keywords that may conflict with the parsing rules defined within Apache Calcite, leading to parsing errors.
• SQL syntax variations between PostgreSQL and Calcite may create incompatibilities, especially when using non-standard or extended SQL features.

Solutions

• Refactor the SQL statements to avoid using reserved keywords directly. For example, use double quotes around identifiers, or choose alternative names.
• Consult the PostgreSQL documentation for a list of reserved keywords and refrain from using these in your queries or treat them as identifiers when necessary.

Mistake: Using PostgreSQL reserved keywords in SQL statements without proper formatting.

Solution: Always double quote identifiers that match reserved keywords.

Mistake: Ignoring syntax differences between PostgreSQL and Apache Calcite.

Solution: Review the Calcite documentation to understand supported SQL syntax and make necessary adjustments.