Re: track generic and custom plans in pg_stat_statements

Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>

From: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>

To: Sami Imseih <samimseih@gmail.com>, Greg Sabino Mullane <htamfids@gmail.com>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2025-03-06T07:56:25Z

Lists: pgsql-hackers

Hi,

Thank you for your patch. It is really useful for tracking the history 
of generic and custom plan usage.

At first glance, I have the following suggestions for improvement:

1. Is there any reason for the double check of cplan != NULL? It seems 
unnecessary, and we could simplify it to:

-if (cplan && cplan->status == PLAN_CACHE_STATUS_CUSTOM_PLAN)
+if (cplan->status == PLAN_CACHE_STATUS_CUSTOM_PLAN)

2. Should we add Assert(kind == PGSS_EXEC) at this place  to ensure that 
generic_plan_calls and custom_plan_calls are only incremented when 
appropriate?

--
Best regards,
Ilia Evdokimov,
Tantor Labs LLC.

Commits

pg_stat_statements: Add counters for generic and custom plans
- 3357471cf9f5 19 (unreleased) landed
Rename CachedPlanType to PlannedStmtOrigin for PlannedStmt
- e125e360020a 19 (unreleased) landed
Introduce field tracking cached plan type in PlannedStmt
- 719dcf3c4226 19 (unreleased) landed