Обсуждение: Re: [JDBC] number of transactions doubling

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Re: [JDBC] number of transactions doubling

От
"Sriram Dandapani"
Дата:
The inserts are applied to a table that has triggers. The trigger has an
exception clause. Each insert is routed based on certain conditions.

Does the presence of an exception clause generate subtransactions
regardless of whether exceptions occurred? If so, do subtransactions
count towards the transaction id wraparound limit counter?

-----Original Message-----
From: Jim Nasby [mailto:jim@nasby.net]
Sent: Friday, September 29, 2006 10:22 AM
To: Heikki Linnakangas
Cc: Sriram Dandapani; pgsql-jdbc@postgresql.org;
pgsql-admin@postgresql.org
Subject: Re: [JDBC] [ADMIN] number of transactions doubling

On Sep 29, 2006, at 4:56 AM, Heikki Linnakangas wrote:
> Jim C. Nasby wrote:
>> On Thu, Sep 28, 2006 at 02:51:24PM -0700, Sriram Dandapani wrote:
>>
>>> The target table has triggers that route data to appropriate
>>> tables. The
>>> tables to which data is routed has check constraints that do further
>>> inserts. (All of this happens in 1 jdbc transaction)
>>>
>>  Actually, no matter what JDBC is doing, all of that will happen
>> within a
>> single transaction on the database (unless you're using something
>> like
>> dblink from within the triggers). So even if you were issuing insert
>> statements with autocommit on, you'd see at most one transaction per
>> insert.
>>
>
> The triggers might use subtransactions. You get implicit
> subtransactions if have an EXCEPTION clause in a plpgsql function.
> I'm not sure if there's other things that do that as well.

Ahh, I thought that was handled within cmin/cmax.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



Re: [JDBC] number of transactions doubling

От
Tom Lane
Дата:
"Sriram Dandapani" <sdandapani@counterpane.com> writes:
> Does the presence of an exception clause generate subtransactions
> regardless of whether exceptions occurred? If so, do subtransactions
> count towards the transaction id wraparound limit counter?

Yes, and yes.

            regards, tom lane