Re: Add comment explaining why queryid is int64 in pg_stat_statements

Thanks for the review.

On Wed, 21 May 2025 at 03:35, Sami Imseih <samimseih(at)gmail(dot)com> wrote:
> 2/ Should "DatumGetInt64(hash_any_extended(......" be turned into a
> macro since it's used in
> several places? Also, we can add a comment in the macro such as
> "
> Output the queryId as an int64 rather than a uint64, to match the
> BIGINT column used to emit
> queryId in system views
> "
>
> I think this comment is needed to address the confusion that is the
> original subject of this thread. Otherwise,
> the confusion will be moved from pg_stat_statements.c to queryjumblefuncs.c

I ended up adding a comment in the Query struct detailing why queryId
is signed. I imagine, as time passes, we might forget why we did that
as hashed values are more naturally unsigned. I think it's wrong to
add comments in DoJumble() to mention details about what the calling
function does. I think the fact that DoJumble() now returns int64
should be a good enough explanation as to why we want to get the hash
value in signed form.

David