Re: Latest version of Hot Standby patch - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Latest version of Hot Standby patch
Date
Msg-id 494B8C66.8080809@enterprisedb.com
Whole thread Raw
In response to Re: Latest version of Hot Standby patch  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Latest version of Hot Standby patch  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
Simon Riggs wrote:
> On Fri, 2008-12-19 at 10:59 +0200, Heikki Linnakangas wrote:
>> Simon Riggs wrote:
>>> * corner case behaviour of backendids - bgwriter writes checkpoint WAL
>>> records. Has no backendid, but needs a slotid (possibly others)
>> Why does bgwriter need a slotid? It doesn't run any transactions.
>>
>>> * slotids are assigned once and never changed, so allowing them to be
>>> used as array lookups directly
>> So are backend ids.
> 
> I'm a little hazy, to be sure. I'm pretty sure there was a blocker, but
> if I cannot recall it we should assume it doesn't exist.
> 
> Where are you going with the thought? Remove slotId from each proc and
> then use backendId to identify the recovery proc?

Yep.

Well, to be honest, I don't much like the whole notion of tracking the 
slots. I think we should just rely on the XLOG_RECOVERY_END records to 
purge stale PGPROC entries, belonging to backends that died without 
writing an abort record.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com


pgsql-hackers by date:

Previous
From: Simon Riggs
Date:
Subject: Re: Latest version of Hot Standby patch
Next
From: Heikki Linnakangas
Date:
Subject: Re: Latest version of Hot Standby patch