Andrei Lepikhov <lepihov@gmail.com> writes:
> I wouldn't recommend this obsolete version of the extension. Since the
> QueryId was introduced, we have redesigned it extensively, with the
> basic idea that QueryId serves as a 'query plan class' and that matching
> parse trees provide a proof of matching incoming queries with their
> corresponding [parameterised] plans.
That's fairly scary, considering all the work that's been done to
intentionally fuzz different queries together to make them look
like "the same query" to pg_stat_statements. While that's fine
for pg_stat_statements, it makes it really questionable to assume
that QueryId is a sufficient proof of semantic equivalence.
(I recall having objected to the whole concept of moving queryjumble.c
into core on the grounds that it could not serve multiple masters.
I think this proves my point...)
regards, tom lane