> To track executed plan types, I think execution layer hooks > are appropriate. > These hooks, however, take QueryDesc as a param and it does > not include cached plan information.
It seems that the same QueryDesc entry is reused when executing a generic plan. For exemple marking queryDesc->plannedstmt->queryId (outside pg_stat_statements) with a pseudo tag during ExecutorStart reappears in later executions with generic plans ...
Is this QueryDesc reusable by a custom plan ? If not maybe a solution could be to add a flag in queryDesc->plannedstmt ?
Thanks for your proposal!
I first thought it was a good idea and tried to add a flag to QueryDesc,
but the comments on QueryDesc say it encapsulates everything that
the executor needs to execute a query.
Whether a plan is generic or custom is not what executor needs to
know for running queries, so now I hesitate to do so.
Instead, I'm now considering using a static hash for prepared queries
(static HTAB *prepared_queries).
BTW, I'd also appreciate other opinions about recording the number
of generic and custom plans on pg_stat_statemtents.
