Re: Separate BLCKSZ for data and logging

On Thu, 16 Mar 2006 19:37:07 +0000
Simon Riggs <simon@2ndquadrant.com> wrote:

> On Thu, 2006-03-16 at 08:21 -0800, Mark Wong wrote:
> 
> > I've been wondering if there might be anything to gain by having a
> > separate block size for logging and data.  I thought I might try
> > defining DATA_BLCKSZ and LOG_BLCKSZ and see what kind of trouble I get
> > myself into.
> > 
> > I wasn't able to find any previous discussion but pehaps 'separate
> > BLKSZ' were poor parameters to use.  Any thoughts?
> 
> I see your thinking.... presumably a performance tuning thought?

Yeah. :)

> Overall, the two things are fairly separate, apart from the fact that we
> do currently log whole data blocks straight to the log. Usually just
> one, but possibly 2 or three. So I have a feeling that things would
> become less efficient if you did this, not more.

I was hoping that in the case where 2 or more data blocks are written to
the log that they could written once within a single larger log block. 
The log block size must be larger than the data block size, of course.

Thanks,
Mark