Re: RFC: Logging plan of the running query

torikoshia <torikoshia@oss.nttdata.com>

From: torikoshia <torikoshia@oss.nttdata.com>

To: pgsql-hackers@lists.postgresql.org

Date: 2022-09-08T10:19:09Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

ecpg: Catch zero-length Unicode identifiers correctly
- a18b6d2dc288 15.0 cited
Improve warning message in pg_signal_backend()
- 7fa945b857cc 15.0 cited
Add assert to ensure that page locks don't participate in deadlock cycle.
- 72e78d831ab5 13.0 cited

Attachments

v23-0001-log-running-query-plan.patch (text/x-diff) patch v23-0001

On 2022-05-16 17:02, torikoshia wrote:
> On 2022-03-09 19:04, torikoshia wrote:
>> On 2022-02-08 01:13, Fujii Masao wrote:
>>> AbortSubTransaction() should reset ActiveQueryDesc to
>>> save_ActiveQueryDesc that ExecutorRun() set, instead of NULL?
>>> Otherwise ActiveQueryDesc of top-level statement will be unavailable
>>> after subtransaction is aborted in the nested statements.
>> 
>> I once agreed above suggestion and made v20 patch making
>> save_ActiveQueryDesc a global variable, but it caused segfault when
>> calling pg_log_query_plan() after FreeQueryDesc().
>> 
>> OTOH, doing some kind of reset of ActiveQueryDesc seems necessary
>> since it also caused segfault when running pg_log_query_plan() during
>> installcheck.
>> 
>> There may be a better way, but resetting ActiveQueryDesc to NULL seems
>> safe and simple.
>> Of course it makes pg_log_query_plan() useless after a subtransaction
>> is aborted.
>> However, if it does not often happen that people want to know the
>> running query's plan whose subtransaction is aborted, resetting
>> ActiveQueryDesc to NULL would be acceptable.
>> 
>> Attached is a patch that sets ActiveQueryDesc to NULL when a
>> subtransaction is aborted.
>> 
>> How do you think?
Attached new patch to fix patch apply failures again.

-- 
Regards,

--
Atsushi Torikoshi
NTT DATA CORPORATION