| From: | Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at> |
|---|---|
| To: | "'pgsql-hackers(at)postgresql(dot)org'" <pgsql-hackers(at)postgresql(dot)org> |
| Cc: | "'t(dot)bussmann(at)gmx(dot)net'" <t(dot)bussmann(at)gmx(dot)net> |
| Subject: | Parallel execution and prepared statements |
| Date: | 2016-11-15 15:41:18 |
| Message-ID: | A737B7A37273E048B164557ADEF4A58B5397E86F@ntex2010i.host.magwien.gv.at |
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| Lists: | pgsql-hackers |
Tobias Bussmann has discovered an oddity with prepared statements.
Parallel scan is used with prepared statements, but only if they have
been created with protocol V3 "Parse".
If a prepared statement has been prepared with the SQL statement PREPARE,
it will never use a parallel scan.
I guess that is an oversight in commit 57a6a72b, right?
PrepareQuery in commands/prepare.c should call CompleteCachedPlan
with cursor options CURSOR_OPT_PARALLEL_OK, just like
exec_prepare_message in tcop/postgres.c does.
The attached patch fixes the problem for me.
Yours,
Laurenz Albe
| Attachment | Content-Type | Size |
|---|---|---|
| 0001-Consider-parallel-plans-for-statements-prepared-with.patch | application/octet-stream | 885 bytes |
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