Re: how to update 400 000 register not at the same time?

From: Shane Ambler <pgsql(at)Sheeky(dot)Biz>
To: John Dizaro <jedsoftware(at)gmail(dot)com>
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: how to update 400 000 register not at the same time?
Date: 2008-12-02 16:30:34
Message-ID: 493562AA.2080203@Sheeky.Biz
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql

John Dizaro wrote:
> I Have um very big table with primary key and all i nead.
> When i update same register from this table it comes sj=low.
> Can i Update all my 400 000 register not at the same time? By steps?
>
> Thanks

Yes - provided you can come up with a definite way to separate your
records into smaller groups.

Use a WHERE clause in your UPDATE -

UPDATE mytable SET col3=56 WHERE col1 IS BETWEEN 1 AND 10000
UPDATE mytable SET col3=56 WHERE col1 IS BETWEEN 10001 AND 20000
...
...

Of course you need to beware that it won't speed things up and you could
run into having other users looking at some old rows at the same time as
some updated rows.

--

Shane Ambler
pgSQL (at) Sheeky (dot) Biz

Get Sheeky @ http://Sheeky.Biz

In response to

Browse pgsql-sql by date

  From Date Subject
Next Message Milan Oparnica 2008-12-02 23:10:59 Re: JOIN results of refcursor functions
Previous Message Pavel Stehule 2008-12-02 05:58:58 Re: JOIN results of refcursor functions