Re: Strange situation with two tables.

From: Terry Yapt <yapt(at)technovell(dot)com>
To: olly(at)lfix(dot)co(dot)uk
Cc: pgsql-novice(at)postgresql(dot)org
Subject: Re: Strange situation with two tables.
Date: 2002-09-11 17:20:32
Message-ID: 1031764832.8167ed0yapt@technovell.com
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Ok, I must to set isolation level to 'serializable' at the function begin, and set isolation level to 'normal mode' at the end.

How can I do it ?

Thanks..

-----Original Message-----
From: Oliver Elphick <olly(at)lfix(dot)co(dot)uk>
To: Terry Yapt <yapt(at)technovell(dot)com>
Date: 11 Sep 2002 16:09:07 +0100
Subject: Re: [NOVICE] Strange situation with two tables.

On Wed, 2002-09-11 at 15:41, Terry Yapt wrote:
> If I understand you and
>
> USER1 starts this pl/pgsql body function
> BEGIN
> SELECT count(*) AS c1 FROM debits;
> ........
> ........ -- Here USER2 INSERTS a new row in debits table. --
> ........
> SELECT count(*) AS c2 FROM debits
> IF c1 = c2 THEN
> RETURN true
> ELSE
> RETURN false
> END IF;
> END;
>
> This functions returns TRUE ? It is right ?

If USER2's transaction has been committed, if the isolation level is
'read committed' the function will return false but if the isolation
level is 'serializable' it will return true.

If USER2's transaction is uncommitted, the function will return true
whatever the isolation level.

--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight, UK
http://www.lfix.co.uk/oliver
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========================================
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now live in the flesh I live by the faith of the Son
of God, who loved me, and gave himself for me."
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