Hi, On 2021-04-26 13:43:31 -0400, Alvaro Herrera wrote: > I think it's straightforward, if we decouple the tri-valued enum used > for guc.c purposes from a separate boolean that actually enables the > feature. GUC sets the boolean to "off" initially when it sees the enum > as "auto", and then pg_stat_statement's _PG_init modifies it during its > own startup as needed.
> So the user can turn the GUC off, and then pg_stat_statement does > nothing and there is no performance drawback; or leave it "auto" and > it'll only compute query_id if pg_stat_statement is loaded; or leave it > on if they want the query_id for other purposes. I think that's the right direction. I wonder though if we shouldn't go a bit further. Have one guc that determines the "query id provider" (NULL or a shared library), and one GUC that configures whether query-id is computed (never, on-demand/auto, always). For the provider GUC load the .so and look up a function with some well known name. Greetings, Andres Freund
