| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Michael Fuhr <mike(at)fuhr(dot)org> |
| Cc: | "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>, Mark <sendmailtomark(at)yahoo(dot)com>, pgsql-general(at)postgresql(dot)org |
| Subject: | Re: query for a time interval |
| Date: | 2005-12-23 15:22:55 |
| Message-ID: | 19830.1135351375@sss.pgh.pa.us |
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| Lists: | pgsql-general |
Michael Fuhr <mike(at)fuhr(dot)org> writes:
> Unless I'm missing something that wouldn't use an index either,
> because the planner wouldn't know what value to compare start_date
> against without hitting each row to find that row's time_to_live.
> But something like this should be able to use an expression index
> on (start_date + time_to_live):
> WHERE start_date + time_to_live < now()
Or perhaps simpler, get rid of time_to_live in favor of an end_date
column, which could be indexed directly.
regards, tom lane
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