Added PostgreSQL v13 VACUUM PARALLEL option support by guptapratykshh · Pull Request #1208 · sqlancer/sqlancer

@guptapratykshh - A few things.

1. We don't want to go the route of server_version_num here. The goal is that ideally SQLancer doesn't need to check the version and should support all commands in the existing / supported version - See this discussion - (as discussed here) .

2. The PR [Postgres][v13] Skip errors around VACUUM FULL not supporting PARALLEL #1053 seems to be on similar lines, and is waiting for v13 support to go live.

3. I think the intention of this PR, to restrict PARALLEL count is understandable, but sometimes restricting search space goes against what the tool is trying to do - in effect that number is intentionally left unrestricted so that if it (negative or very large int) triggers the engine to go wild, then so be it.