On 09.11.2011 15:25, Simon Riggs wrote:
> On Wed, Nov 9, 2011 at 9:06 AM, Heikki Linnakangas
> <heikki.linnakangas@iki.fi> wrote:
>> In COPY, insert tuples to the heap in batches.
>>
>> This greatly reduces the WAL volume, especially when the table is narrow.
>> The overhead of locking the heap page is also reduced. Reduced WAL traffic
>> also makes it scale a lot better, if you run multiple COPY processes at
>> the same time.
>
> Sounds good.
>
> I can't see where this applies backup blocks. If it does, can you
> document why/where/how it differs from other WAL records?
Good catch, I missed that. I copied the redo function from normal
insertion, but missed that heap_redo() takes care of backup blocks for
you, while heap2_redo() does not.
I'll go fix that..
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com
