| From: | twoflower <standa(dot)kurik(at)gmail(dot)com> |
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Re: Query > 1000× slowdown after adding datetime comparison |
| Date: | 2015-08-31 19:46:56 |
| Message-ID: | 1441050416677-5864088.post@n5.nabble.com |
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| Lists: | pgsql-performance |
David G Johnston wrote
> What happens if you pre-compute the date condition and hard code it?
I created a new boolean column and filled it for every row in DOCUMENT with
*(doc.date_last_updated >= date(now() - '171:00:00'::interval))*, reanalyzed
the table and modified the query to just compare this column to TRUE. I
expected this to be very fast, considering that a (to me, anyway) similar
query also containing a constant value comparison finishes immediately.
However, the query is running now for 4 minutes already. That's really
interesting.
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