From: Tino Wildenhain <tino@wildenhain.de>
To: Thomas Vatter <thomas.vatter@network-inventory.de>
Cc: pgsql-performance@postgresql.org
Subject: Re: in memory views
Date: Wed, 10 May 2006 12:08:30 +0200
Message-ID: <4461BB9E.5030607@wildenhain.de> (raw)
In-Reply-To: <4461B899.4030502@network-inventory.de>
References: <4461AFFF.7060200@network-inventory.de>
<4461B3DE.6030700@wildenhain.de>
<4461B899.4030502@network-inventory.de>
Thomas Vatter schrieb:
> Tino Wildenhain wrote:
>
>> Thomas Vatter schrieb:
>>
>>> is there a possibility for creating views or temp tables in memory to
>>> avoid disk io when user makes select operations?
>>
>>
>>
>> No need. The data will be available in OS and database caches if
>> they are really required often. If not, tune up the caches and
>> do a regular "pre select".
>>
>> Regards
>> Tino
>>
>>
>
> hmm, I am selecting a resultset with 1300 rows joined from 12 tables.
> with jdbc I am waiting 40 seconds until the first row appears. The
> following rows appear really fast but the 40 seconds are a problem.
Well you will need the equally 40 seconds to fill your hypothetical
in memory table. (even a bit more due to the creation of a datastructure).
So you can do the aproaches of semi materialized views (that are in fact
writing into a shadow table) or just prefetch your data at time - just
at the times you would refill your memory tables if they existed.
A cronjob with select/fetch should do.
Regards
Tino
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tino@wildenhain.de, thomas.vatter@network-inventory.de
Subject: Re: in memory views
In-Reply-To: <4461BB9E.5030607@wildenhain.de>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox