On Tue, Nov 12, 2013 at 2:47 PM, Tom Lane t...@sss.pgh.pa.us wrote:
That's right, we store 90 days and roll up data older than that into a
different table.
Ah-hah. The default statistics target is 100, so indeed ANALYZE is going
to be able to fit every date entry in the table into the
Kevin Goess kgo...@bepress.com writes:
We noticed a big change after upgrading from 9.0 to 9.2. For
*yesterday's*date, the query plan is fine, like you'd expect
articles_1= explain (analyze, buffers) select 1
from hits_user_daily_count
where userid = 1590185 and date =
Thanks for the reply!
Your analysis matches everything I see here, so what you say is probably
the case. As to why it changed for us with the 9.0 = 9.2 upgrade, I also
don't know--the change was pretty dramatic though. Since we've compensated
for it, and since you say the current behavior is
Kevin Goess kgo...@bepress.com writes:
Now, the only way to get to a zero selectivity estimate for var = const
is if the planner believes that the pg_stats most-common-values list
for the column is complete, and the constant is nowhere in the list.
So one plausible explanation for the change
Given this table
articles_1= \d hits_user_daily_count;
Table public.hits_user_daily_count
Column | Type | Modifiers
---+-+---
userid| integer | not null
date | date| not null
