Re: setFetchSize - Mailing list pgsql-jdbc

From John R Pierce
Subject Re: setFetchSize
Date
Msg-id 4EA88BBA.4010005@hogranch.com
Whole thread Raw
In response to Re: setFetchSize  (fschmidt <fschmidt@gmail.com>)
Responses Re: setFetchSize
List pgsql-jdbc
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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