Re: [survey] New "Stable" QueryId based on normalized query text

On Mon, Aug 12, 2019 at 4:01 PM Evgeniy Efimkin <efimkin@yandex-team.ru> wrote:
>
> > One problem with pg_stat_statement's normalized query is that it's not
> > stable, it's storing the normalized version of the first query string
> > passed when an entry is created. So you could have different strings
> > depending on whether the query was fully qualified or relying on
> > search path for instance.
> I think normalized query stored in pg_stat_statement it's not very important.
> it might look something like that
> `
>          query         | calls |  queryid   |  sql_id
> -----------------------+-------+------------+------------
>  Select * from   t     |     4 |  762359559 |  680388963
>  select * from t       |     7 | 3438533065 |  680388963
>  select * from test2.t |     1 |  230362373 |  680388963
> `
> we can cut schema name in sql normalization
> algorithm

Not only schema name but all kind of qualification and indeed extra
whitespaces. Things get harder for other difference that aren't
meaningful (LIKE vs ~~, IN vs = ANY...).  That would also imply that
everyone wants to ignore schemas in query normalization, I'm not sure
how realistic that is.