Re: setFetchSize

From: John R Pierce <pierce(at)hogranch(dot)com>
To: pgsql-jdbc(at)postgresql(dot)org
Subject: Re: setFetchSize
Date: 2011-10-26 22:37:46
Message-ID: 4EA88BBA.4010005@hogranch.com
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On 10/26/11 1:22 PM, fschmidt wrote:
> Dave Cramer-8 wrote:
>> >
>> > My understanding is this: Postgresql is an MVCC database and can
>> > easily provide you with a snapshot of a resultset inside a
>> > transaction. Outside a transaction my bet is that the data has to be
>> > copied to a temporary location somewhere, so if this is done over N
>> > connections the resources required could be substantial.
>> >
> The solution is very simple. Just keep the version associated with the
> current resultset around until the resultset is closed. This is basically
> the same as having another connection, but in this case, each resultset on
> the connection should use the version that was associated with the
> connection when the resultset was opened.

so now vacuum needs to pay attention to the oldest pending result set as
well as the oldest transaction?

hmmm.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

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