| From: | Etsuro Fujita <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Problems with plan estimates in postgres_fdw |
| Date: | 2018-12-28 06:50:29 |
| Message-ID: | 5C25C7B5.2010802@lab.ntt.co.jp |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
(2018/12/26 16:35), Etsuro Fujita wrote:
> Attached is an updated version of the patch. Other changes:
While self-reviewing the patch I noticed a thinko in the patch 0001 for
pushing down the final sort: I estimated the costs for that using
estimate_path_cost_size that was modified so that it factored the
limit_tuples limit (if any) into the costs, but I think that was wrong;
that should not factor that because the remote query corresponding to
the pushdown step won't have LIMIT. So I fixed that. Also, a new data
structure I added to include/nodes/relation.h (ie, OrderedPathExtraData)
is no longer needed, so I removed that. Attached is a new version of
the patch.
Best regards,
Etsuro Fujita
| Attachment | Content-Type | Size |
|---|---|---|
| 0001-postgres_fdw-Perform-UPPERREL_ORDERED-step-remotely-v2.patch | text/x-patch | 43.9 KB |
| 0002-postgres_fdw-Perform-UPPERREL_FINAL-step-remotely-v2.patch | text/x-patch | 95.4 KB |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Pavel Stehule | 2018-12-28 06:57:45 | Re: plpgsql plugin - stmt_beg/end is not called for top level block of statements |
| Previous Message | Thomas Munro | 2018-12-28 05:45:20 | Re: Compiling on Termux |