On Fri, Oct 4, 2024 at 5:05 PM Anthonin Bonnefoy
<anthonin.bonnefoy@datadoghq.com> wrote:
>
> I agree that tracking 2 identical statements with different queryIds
> and nesting levels is very confusing. On the other hand, from an
> extension developer point of view (not necessarily limited to
> pg_stat_statements), I would like to have the queryId available and
> the post_parse hook called so the query can be normalised and tracked
> in a hashmap.
>
> However, the repeated statements did bug me a lot so I took a stab at
> trying to find a possible solution. I made an attempt in 0001 by
> tracking the statements' locations of explainable statements (Select,
> Insert, Update, Merge, Delete...) during parse and propagate them in
> the generated Query during transform. With the change, we now have the
> following result:
>
> SET pg_stat_statements.track = 'all';
> explain (costs off) select 1;
> select 1;
> select queryid, calls, query, toplevel from pg_stat_statements
> where query ~'select \$1';
> queryid | calls | query | toplevel
> ---------------------+-------+-------------------------------+----------
> 2800308901962295548 | 1 | select $1 | t
> 2800308901962295548 | 1 | select $1; | f
> 3797185112479763582 | 1 | explain (costs off) select $1 | t
>
> The top level and nested select statement now share both the same
> queryId and query string. The additional ';' for the nested query is
> due to not having the statement length and taking the whole
> statement.
>
about v5 0001
select_with_parens:
'(' select_no_parens ')' { $$ = $2; }
| '(' select_with_parens ')' { $$ = $2; }
;
toplevel | calls | query
----------+-------+-------------------------------------------------------
t | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
t | 0 | SELECT toplevel, calls, query FROM pg_stat_statements+
| | ORDER BY query COLLATE "C", toplevel
t | 1 | explain (select $1)
f | 1 | select $1);
query "select $1);" looks weird. not sure how to improve it,
or this should be the expected behavior?
in gram.y
| values_clause { $$ = $1; }
| TABLE relation_expr
for TABLE relation_expr
we can add `n->location = @1;`
for values_clause we can do also,
then in transformValuesClause do the same as in transformSelectStmt.
