Re: pgsql: Update item description: * Considerhaving the background writer

Simon Riggs wrote:
> On Mon, 2007-12-17 at 01:40 +0000, Bruce Momjian wrote:
>> Log Message:
>> -----------
>> Update item description:
>>
>> * Consider having the background writer update the transaction status
>>   hint bits before writing out the page
>>
>>   Implementing this requires the background writer to have access to system
>>   catalogs and the transaction status log.
>
> Not very sure why you've added this one to the TODO list?
>
> I raised it as not-a-good idea and I think Tom and Alvaro agreed. i.e. I
> mentioned it in order to kill it. It's a ton of work for what very well
> might be overhead rather than gain.

I actually do feel it might be valuable. All our opinions are based on
gut-feeling, though, so would need benchmarking to see if it's really
worth it or not.

I think we could get away without accessing system catalogs in bgwriter,
if we flagged heap pages as such in ReadBuffer. Just a thought..

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