On Tue, Dec 3, 2013 at 6:03 AM, Heikki Linnakangas
<hlinnakangas@vmware.com> wrote:
> The log_newpage function, used to WAL-log a full copy of a page, is missing
> the trick we normally use for full-page images to leave out the unused space
> on the block. That's pretty trivial to implement, so we should.
>
> The place where this matters the most is when building a new B-tree index.
> When wal_level > minimal, all pages in the created index are logged with
> log_newpage, and by default we leave 10% free space on index pages. So
> implementing this reduces the amount of WAL generated by index creation by
> roughly 10%.
>
> Anyone see a problem with this?
Looks good to me.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company