| From: | Kris Jurka <books(at)ejurka(dot)com> |
|---|---|
| To: | David Fetter <david(at)fetter(dot)org> |
| Cc: | PG Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Top-k optimizations? |
| Date: | 2005-01-14 04:07:55 |
| Message-ID: | Pine.BSO.4.56.0501132302300.32384@leary.csoft.net |
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| Thread: | |
| Lists: | pgsql-hackers |
On Thu, 13 Jan 2005, David Fetter wrote:
> 3. What kinds of top-k optimizations might (eventually) be included
> in PostgreSQL?
>
See the TODO item:
Allow ORDER BY ... LIMIT 1 to select high/low value without sort or index
using a sequential scan for highest/lowest values
If only one value is needed, there is no need to sort the entire table.
Instead a sequential scan could get the matching value.
There is some discussion of this on the -general list here:
Kris Jurka
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