Thanks for the link. I've done some more reading, and now it appears impossible to set the isolation level of a transaction from within a function.
CREATE OR REPLACE FUNCTION test(character varying)
RETURNS integer AS
$BODY$
BEGIN
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
RETURN 1;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
Creates successfully, but when executed reports : "ERROR: SET TRANSACTION ISOLATION LEVEL must be called before any query". I believe this is happening because I'm exercising the function with :
select * from test('test');
so that select is executed prior to the SET TRANSACTION. If I remove the SET TRANSACTION command from the function, and then call it by :
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
select * from test('test');
that works. So, is that the correct way to set the isolation level for a function? Thanks again for your help.
On Tue, Nov 2, 2010 at 5:13 AM, Thom Brown
<thom@linux.com> wrote:
On 2 November 2010 01:51, Joe Carr
<joe.carr@gmail.com> wrote:
In version 9.0, I've been reading http://www.postgresql.org/docs/9.0/interactive/sql-begin.html. I've been using the following :
CREATE OR REPLACE FUNCTION test(character varying)
RETURNS SETOF integer AS
$BODY$
BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
--SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
RETURN 1;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
which returns with the error :
ERROR: syntax error at or near "TRANSACTION"
LINE 1: TRANSACTION ISOLATION LEVEL SERIALIZABLE
if the BEGIN line is empty with no semi-colon, the function will work :
CREATE OR REPLACE FUNCTION test(character varying)
RETURNS integer AS
$BODY$
BEGIN
--TRANSACTION ISOLATION LEVEL SERIALIZABLE;
--SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
RETURN 1;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
but if I place a semi-colon after BEGIN (e.g. BEGIN;), I get the error :
ERROR: syntax error at or near ";"
LINE 5: BEGIN;
So any help you may be able to provide in the BEGIN syntax (or whatever I'm doing wrong) is greatly appreciated. Thanks!
-Joe
--
Thom Brown
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