| From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
|---|---|
| To: | Praveen Kumar N <praveen_n(at)students(dot)iiit(dot)net> |
| Cc: | Heikki Linnakangas <heikki(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: postgresql shared buffers |
| Date: | 2006-09-08 16:53:18 |
| Message-ID: | 20060908165318.GX5892@alvh.no-ip.org |
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| Lists: | pgsql-hackers |
Praveen Kumar N wrote:
>
> one more doubt.in the following example we dont need sort right.But in
> this case also relations were scanned sequentially one by one.
In this case it's because the result from one seqscan was materialized.
> So is it the
> case that any relation is accessed only once from database while executing
> a given query?
Not in general -- you'll see that behavior only in particular cases.
--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
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