| From: | Adrien Nayrat <adrien(dot)nayrat(at)dalibo(dot)com> |
|---|---|
| To: | PostgreSQL mailing lists <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | auto_explain : log queries with wrong estimation |
| Date: | 2017-08-24 11:56:20 |
| Message-ID: | 55d18a40-d99f-eccc-7323-62e0806ad7a6@dalibo.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Hi hackers,
I try to made a patch to auto_explain in order to log queries with wrong estimation.
I compare planned row id : queryDesc->planstate->plan->plan_rows
Vs ntuples : queryDesc->planstate->instrument->ntuples;
If I understand, instrumentation is used only with explain. So my patch works
only with explain (and segfault without).
Is there a simple way to get ntuples?
Attached a naive patch.
Thanks :)
--
Adrien NAYRAT
| Attachment | Content-Type | Size |
|---|---|---|
| log_wrong_estimation_v1.path | text/plain | 3.3 KB |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas Munro | 2017-08-24 12:08:08 | Re: POC: Sharing record typmods between backends |
| Previous Message | Thomas Munro | 2017-08-24 11:08:52 | MCXT_ALLOC_NO_OOM -> DSA_ALLOC_NO_OOM in dsa.c |