Re: Freeze avoidance of very large table.

On 04/22/2015 09:24 PM, Robert Haas wrote:
>> I would feel safer if we added a completely new "epoch" counter to the page
>> >header, instead of reusing LSNs. But as we all know, changing the page
>> >format is a problem for in-place upgrade, and takes some space too.
> Yeah.  We have a serious need to reduce the size of our on-disk
> format.  On a TPC-C-like workload Jan Wieck recently tested, our data
> set was 34% larger than another database at the beginning of the test,
> and 80% larger by the end of the test.  And we did twice the disk
> writes.  See "The Elephants in the Room.pdf" at
> https://sites.google.com/site/robertmhaas/presentations

Meh. Adding an 8-byte header to every 8k block would add 0.1% to the 
disk size. No doubt it would be nice to reduce our disk footprint, but 
the page header is not the elephant in the room.

- Heikki