Re: php with postgres

Hello Bruce,

Thursday, July 24, 2003, 11:05:21 PM, you wrote:

BM> Marcus B?rger wrote:
>> >> BM> I don't see why you wouldn't just do BEGIN;COMMIT;RESET ALL; when you
>> >> BM> pass the connection to a new client.
>> >>
>> >>
>> >> Bruce you said RESET ALL is available since 7.2. I am currently checking for
>> >> the lib version but it would be more correct to check something on the server.
>> >> So the question what do i check?
>>
>> BM> We usually use SELECT version().
>>
>>
>> ATM i have a patch doing the following:
>> Connect:
>> If PQprotocolVersion() is available and >= 3 PQparameterStatus() is available
>> then i check the server version. Else i check the lib version (*).
>> If the version to check is >= 7.2 ido one of the following:
>> - If one of PQprotocolVersion() and PQtransactionStatus() is unavailable or
>> protocol version < 3:
>> "BEGIN;COMMIT;RESET ALL;"

BM> I believe this should be BEGIN;ROLLBACK;RESET ALL; because our default
BM> for a client that disconnects is to abort the transaction.

>> - If protocol version >= 3 and transaction status == PQTRANS_IDLE:
>> "RESET ALL;"
>> - If protocol version >= 3 and transaction status != PQTRANS_IDLE:
>> "COMMIT;RESET ALL;"

BM> Should be "ROLLBACK;RESET ALL;".

Because of above mentioned default?
The problem i have is that now we do the COMMIT - so this behavior change can
only go into php 5 with a big notice.

BM> Nice version test code, sounds good.

>>
>> Disconnect:
>> - When PQprotocolVersion() And PQtransactionStatus() are available then
>> i check whether status is PQTRANS_IDLE. If so i do:
>> "ROLLBACK;"
>> - If the functions are not available in the client libs i do:
>> "BEGIN;ROLLBACK;"
>>
>> Does this sound the correct behavior?

BM> I am confused why you are doing stuff on connect and disconnect. Seems
BM> it should all be done on disconnect so you don't leave open transactions
BM> in the pooled connections --- it will keep locks around too long and
BM> reduce the usefulness of vacuum. If we clean up everything on
BM> disconnect, aren't we sure that the connection status will be fine?

>> And would "select split_part(version(), ' ', 2);" be too much of a slowdown to
>> do the version detection in the startup sequence completely correct?

BM> Seems fine. Since you are doing pooled connections, you shouldn't be
BM> doing this too often anyway.

I believe the point was "RESET ALL;". But maybe i can move all but that into
shutdown. I mean for me that sounds good. Only someone must enlighten me if
there could be a problem with that reset.

--
Best regards,
Marcus mailto:marcus(dot)boerger(at)post(dot)rwth-aachen(dot)de