Samuel Gendler writes:
> fast plan: http://explain.depesz.com/s/iZ
> slow plan: http://explain.depesz.com/s/Dv2
Your problem here is that it's switching from hash aggregation to
sort-and-group-aggregate once it decides that the number of aggregate
groups won't fit in work_mem anymore. While you
The full set of conf changes that were in use during these tests are as
follows:
default_statistics_target = 100 # pgtune wizard 2010-08-17
maintenance_work_mem = 1GB # pgtune wizard 2010-08-17
constraint_exclusion = on # pgtune wizard 2010-08-17
checkpoint_completion_target = 0.9 # pgtune wizard
On Wed, Aug 18, 2010 at 11:14 PM, Samuel Gendler
wrote:
> Please forgive the barrage of questions. I'm just learning how to tune
> things in postgres and I've still got a bit of learning curve to get over,
> apparently. I have done a lot of reading, though, I swear.
>
> I've got two identical qu
Please forgive the barrage of questions. I'm just learning how to tune
things in postgres and I've still got a bit of learning curve to get over,
apparently. I have done a lot of reading, though, I swear.
I've got two identical queries except for a change of one condition which
cuts the number o
