| From: | "Gary Doades" <gpd(at)gpdnet(dot)co(dot)uk> |
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: planner/optimizer question |
| Date: | 2004-04-28 07:08:03 |
| Message-ID: | 408F6663.22977.CC6AF7D@localhost |
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| Lists: | pgsql-performance |
I can understand the performance loss on non-selects for keeping the
index validity state tracking the row validity, but would that outweigh the
performance gains on selects? Depends on your mix of selects to non
selects I guess, but other database systems seem to imply that keeping
the index on track is worth it overall.
Cheers,
Gary.
On 28 Apr 2004 at 15:04, Christopher Kings-Lynne wrote:
> > Why is there an entry in the index for a row if the row is not valid?
> > Wouldn't it be better for the index entry validity to track the row validity.
> > If a particular data value for a query (join, where etc.) can be satisfied
> > by the index entry itself this would be a big performance gain.
>
> For SELECTs, yes - but for INSERT, UPDATE and DELETE it would be a big
> performance loss.
>
> Chris
>
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