On Mon, Apr 23, 2007 at 07:20:29PM +0200, Arkadiusz Raj wrote:
> I have a table in my database that is updated every minute with new acquired
> data. Anyway there is a query to get latest values to be displayed on
> screen. I have postgresql 7.4.2 that work very fine.
You want _at least_ the latest 7.4 version -- ideally, the latest 8.2
> The problem was that
> after hdd crash I have rebuild database from the archive and... Execution
> time of this query starts to be unacceptable.
Have you re-ANALYZEd after the data load?
Anyhow, the issue with the planner not knowing how to estimate expressions
like "now() - interval '5 minutes'" correctly is a known 7.4 issue, and it's
fixed in later versions. It might have worked more or less by accident
earlier, although it seems odd that it wouldn't even have considered the
/* Steinar */