On Mon, Jan 3, 2011 at 11:36 AM, Florian Pflug <fgp@phlo.org> wrote:
> On Jan3, 2011, at 17:21 , Robert Haas wrote:
>> On Mon, Jan 3, 2011 at 11:08 AM, Heikki Linnakangas
>>> In serializable mode you get a serialization error.
>>
>> I don't think this part is true. You can certainly do this:
>>
>> CREATE TABLE test (a int);
>> BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>> SELECT * FROM test;
>> <in another session, insert (1) into test>
>> LOCK TABLE test IN SHARE MODE; -- or just LOCK TABLE test, if you prefer
>> SELECT * FROM test; -- still ain't there
>> INSERT INTO test VALUES (1);
>
> In SERIALIZABLE mode, you need to take any table-level locks before obtaining
> a snapshot. There's even a warning about this in the docs somewhere IIRC...
That should be safe, if people do it that way.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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