Re: why partition pruning doesn't work?

Andrew Dunstan <andrew.dunstan@2ndquadrant.com>

From: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>

To: Tom Lane <tgl@sss.pgh.pa.us>, David Rowley <david.rowley@2ndquadrant.com>

Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Dmitry Dolgov <9erthalion6@gmail.com>, Jeff Janes <jeff.janes@gmail.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Pavel Stehule <pavel.stehule@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2018-06-12T11:47:16Z

Lists: pgsql-hackers


On 06/11/2018 06:41 PM, Andrew Dunstan wrote:
>
>
> On 06/11/2018 06:24 PM, Tom Lane wrote:
>>
>> If we had any buildfarm critters running valgrind on
>> RELCACHE_FORCE_RELEASE or CLOBBER_CACHE_ALWAYS builds, they'd have
>> detected use of uninitialized memory here ... but I don't think we have
>> any.  (The combination of valgrind and CCA would probably be too slow to
>> be practical :-(, though maybe somebody with a fast machine could do
>> the other thing.)
>>
>>
>
>
> I don't have a fast machine, but I do have a slow machine already 
> running valgrind and not doing much else :-) Let's see how lousyjack 
> does with -DRELCACHE_FORCE_RELEASE
>
>


It added about 20% to the run time. That's tolerable, so I'll leave it on.

cheers

andrew

-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

Fix up run-time partition pruning's use of relcache's partition data.
- e23bae82cf3d 11.0 landed
Fix access to just-closed relcache entry.
- bdc643e5e46f 11.0 landed
- b10edaf4bb44 10.5 landed
Improve ExecFindInitialMatchingSubPlans's subplan renumbering logic.
- 69025c5a07a1 11.0 landed
Improve commentary about run-time partition pruning data structures.
- 4e2323640333 11.0 landed
Fix run-time partition pruning code to handle NULL values properly.
- be3d90026a3c 11.0 landed
Assorted cosmetic cleanup of run-time-partition-pruning code.
- 321f648a312b 11.0 landed
Relocate partition pruning structs to a saner place.
- 939449de0e57 11.0 landed
Improve run-time partition pruning to handle any stable expression.
- 73b7f48f78d2 11.0 landed
Support partition pruning at execution time
- 499be013de65 11.0 cited