Re: Please consider removing "select count(*)..."

From: Andreas Pflug <Andreas(dot)Pflug(at)web(dot)de>
To: Dave Page <dpage(at)vale-housing(dot)co(dot)uk>, pgadmin-hackers(at)postgresql(dot)org, ybaykshtis(at)aurigin(dot)com
Subject: Re: Please consider removing "select count(*)..."
Date: 2003-05-23 22:48:43
Message-ID: 3ECEA54B.70406@web.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgadmin-hackers

Dave Page wrote:

>
>
>>-----Original Message-----
>>From: Yurgis Baykshtis [mailto:ybaykshtis(at)aurigin(dot)com]
>>Sent: 23 May 2003 19:46
>>To: pgadmin-hackers(at)postgresql(dot)org
>>Subject: [pgadmin-hackers] Please consider removing "select
>>count(*)..."
>>
>>
>>In both pgAdmin 2 and 3, whenever I click on a table node in
>>the object tree, for a table with relatively big number of
>>rows, it's taking a very long time to update the property
>>panel (up to a few minutes with very high CPU load by the
>>postgres process) making practically impossible usage of the
>>tool. The reason is in the "select count(*)" query pgAdmin
>>use to get table row count.
>>I am not sure whether there is another way to count table
>>rows in Postgres, but I see it does not like 'select
>>count(*)' much for large tables.
>>
>>I just commented out this query for myself forcing row count
>>field to be always zero and it works just fine for me.
>>
>>
>
>Hi Yurgis,
>
>I've now added an option for this to the pgAdmin III CVS.
>
>
Didn't think this would be an issue so early.
I planned to implement this with a threshold level. We have
rowsEstimated, which should (hopefully) be more or less up-to-date if
VACUUMed properly, and if e.g. 100,000 rows (configurable) are exceeded
a count(*) is suppressed and only performed on explicit refresh.

Yurgis, you seem to have large tables, which default threshold seems
reasonable to you? 10k rows? 100k?

Regards,
Andreas

In response to

Browse pgadmin-hackers by date

  From Date Subject
Next Message Yurgis Baykshtis 2003-05-23 22:53:42 Re: Please consider removing "select count(*)..."
Previous Message Yurgis Baykshtis 2003-05-23 20:26:43 Re: Please consider removing "select count(*)..."