Обсуждение: [PATCH] Referenced generic plan mode

Hi all,

I’d like to propose a patch that introduces a referenced generic plan mode.

The patch adds:

• new EXPLAIN option REF_GENERIC_PLAN (not allowed with ANALYZE);

• new plan_cache_mode values ref_auto and force_ref_generic_plan;

• a flag to prevent constant folding of Params when building a generic plan.

Generic and custom plan behavior stays unchanged unless the new option is used.
Similar ideas exist in other systems: Oracle (Adaptive Cursor Sharing), SQL Server (Parameter Sensitive Plan Optimization), and Db2 (REOPT).

I’ve attached the patch and a minimal regression test.

Best regards,
Vlada Pogozhelskaya