| From: | mike <mike(at)Reifenberger(dot)com> |
|---|---|
| To: | Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> |
| Cc: | pgsql-bugs(at)postgresql(dot)org |
| Subject: | Re: index not used afer VACUUM ANALYZE |
| Date: | 2003-08-27 15:43:50 |
| Message-ID: | 20030827173917.A2975-300000@mike.reifenberger.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs |
Hi,
On Tue, 26 Aug 2003, Stephan Szabo wrote:
...
> But does it change the amount of time the query actually takes to run?
> seqscans are not always slower nor are they necessarily the actual problem
> here. The problem seems to be choosing a group aggregate + sort which is
> taking alot of time, if you look at the real time on the steps below that
> it's approximately the same for seqscan or index scan.
Ok, with plenty of sort_mem (327680) the seqscan seems to be faster.
Using 64000 shared_buffers it's not that amazing since nothing hits the disks.
As last times aus1.txt is before aus2.txt after the VACUUM ANALYZE.
Bye/2
---
Michael Reifenberger, Business Unit Manager SAP-Basis, Plaut Consulting
Comp: Michael(dot)Reifenberger(at)plaut(dot)de | Priv: Michael(at)Reifenberger(dot)com
http://www.plaut.de | http://www.Reifenberger.com
| Attachment | Content-Type | Size |
|---|---|---|
| aus1.txt | text/plain | 3.6 KB |
| aus2.txt | text/plain | 3.5 KB |
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