|From:||Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>|
|To:||Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>|
|Cc:||Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>, craig(dot)ringer(at)2ndquadrant(dot)com, robertmhaas(at)gmail(dot)com, PostgreSQL Developers <pgsql-hackers(at)postgresql(dot)org>|
|Subject:||Re: BUG: pg_stat_statements query normalization issues with combined queries|
|Views:||Raw Message | Whole Thread | Download mbox | Resend email|
>> Yeah, that's what I was thinking of. There aren't very many places that
>> would need to know about that, I believe; [...]
> For fixing the information in pg_stat_statement, the location data must be
> transported from the parsed node to the query to the planned node, because
> the later two nodes types are passed to different hooks.
> Now the detail is that utility statements, which seems to be nearly all of
> them but select/update/delete/insert, do not have plans: The statement itself
> is its own plan... so there is no place to store the location & length.
Here is an updated version:
Changes wrt v2:
- I have added the missing stuff under /nodes/, this is stupid code that
should be automatically generated:-(
- I have added comments in "gram.y" about how the length is computed.
I have also slightly simplified the rule code there.
- I have rename "location" in create table space to "location_dir"
to avoid confusion.
- I have renamed the fields "location" and "length" instead of q*.
- I have moved the location & lenth copies in standard_planner.
- I have fixed the function declaration typo.
- I have simplified pgss_store code to avoid a copy, and move the
length truncation in qtext_store.
- I have improved again the pg_stat_statement regression tests with
combined utility statement tests, which implied some fixes to
extract the right substring for utility queries.
However, not changed:
- I cannot use the intermediate node trick suggested by Tom because
it does not work for utility statements which do not have plans, so
the code still adds location & length, sorry.
- I still use the 'last_semicolon' lexer variable. The alternative is to
change rules so as not to skip empty statements, then write a loop to
compute the length based on successor location, and remove the empty
statements. It can be done, I do not think it is better, it is only
different and more verbose. I'll do it if required by a committer.
|Next Message||Yuriy Zhuravlev||2016-12-30 14:10:45||Re: WIP: About CMake v2|
|Previous Message||Pavel Stehule||2016-12-30 14:07:56||Re: proposal: session server side variables|