Re: Trigger on select?

On Tue, Aug 02, 2005 at 05:54:59PM -0700, Chris Travers wrote:

> >Hey, anyone know if it is possible to fire a trigger before a select?
> >I'm considering creating some tables which contain data summarized
> >from other tables as kind of a cache mechanism. The hope is I can
> >speed up some queries that get executed a lot (and are kind of slow)
> >by maintaining data (like sums of big columns, for example). I was
> >all ready to go and then I discovered that trigger-before-select is
> >not supported. (Is it in any DB?)
> >
> >The idea is this:
> >
> >Any time I execute a query that would access the summary data, the
> >"before select" trigger fires and goes out and builds any summary data
> >missing from the summary table.
>
> No. You must instead generate a view.

And then it needs to be a materialized view of some sort
to achieve the caching he's after.

Karsten
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