Florian Pflug wrote:
> Heikki Linnakangas wrote:
>> That's a pretty sensitive tradeoff, we want to prune often to cut the
>> long HOT chains, but not too often because it's pretty expensive to
>> acquire the vacuum lock and move tuples around. I don't think we've
>> found the optimal solution yet. Separating the pruning and defragmenting
>> might help.
>
> Does defragmenting force writing a full page image to the WAL afterwards?
> Or does it just log the fact that the page was defragmented, and the actual
> work is redone on recovery?
No, you just log a note that it was defragmented.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
