Re: track_planning causing performance regression

On Tue, Jun 29, 2021 at 10:45 AM Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote:
>
> We borrowed that language from the previous text:
>
> | Plannable queries (that is, SELECT, INSERT, UPDATE, and DELETE) are combined into a single pg_stat_statements entry whenever they have identical query structures according to an internal hash calculation

Yes, but here's it's "identical query structure", which seems less
ambiguous than "identical structure" as iI think one could think it
refer to internal representation as much as as the query text. And
it's also removing any doubt with the final "internal hash
calculation".

> Really, I'm only trying to fix where it currently says "a fewer kinds".

I agree that "fewer kinds" should be improved.

> Enabling this parameter may incur a noticeable performance penalty,
> - especially when a fewer kinds of queries are executed on many
> - concurrent connections.
> + especially when queries with identical structure are executed by many
> + concurrent connections which compete to update a small number of
> + pg_stat_statements entries.
>
> It could say "identical structure" or "the same queryid" or "identical queryid".

I think we should try to reuse the previous formulation. How about
"statements with identical query structure"? Or replace query
structure with "internal representation", in both places?