Re: Hot standby, recovery procs - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Hot standby, recovery procs
Date
Msg-id 1235507128.16176.228.camel@ebony.2ndQuadrant
Whole thread Raw
In response to Re: Hot standby, recovery procs  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: Hot standby, recovery procs  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
On Tue, 2009-02-24 at 21:59 +0200, Heikki Linnakangas wrote:
> We only need the lsn atrribute because we when we take the snapshot
> of 
> running xids, we don't write it to the WAL immediately, and a new 
> transaction might begin after that. If we close that gap in the
> master, 
> we don't need the lsn in recovery procs.
> 
> Actually, I think the patch doesn't get that right as it stands:
> 
> 0. Transactions 1 is running in master
> 1. Get list of running transactions
> 2. Transaction 1 commits.
> 3. List of running xacts is written to WAL
> 
> When the standby replays the xl_running_xacts record, it will create
> a 
> recovery proc and mark the transaction as running again, even though
> it 
> has already committed.

No, because we check whether TransactionIdDidCommit().

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support



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