On Fri, May 11, 2012 at 2:03 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
> On Thu, May 10, 2012 at 10:44 AM, Bruce Momjian <bruce@momjian.us> wrote:
>> On Thu, May 10, 2012 at 01:11:54PM +0100, Peter Geoghegan wrote:
>>
>>> Why can't we call group commit group commit (and for that matter,
>>> index-only scans index-only scans), so that people will understand
>>> that we are now competitive with other RDBMSs in this area? "Improve
>>> performance of WAL writes when multiple transactions commit at the
>>> same time" seems like a pretty bad description, since it doesn't make
>>> any reference to batching of commits. Also, I don't think that the
>>
>> I didn't call it "group commit" because we have settings we used to
>> regard as group commit:
>
> My understanding of that patch is that is does not cause "group
> commit" to happen, but rather when a group commit does happen
> "naturally" it causes all members of the group to awaken more
> quickly/efficiently than they previously would have.
Right. It's not a new feature; it's a performance improvement. We've
had group commit for a long time; it just didn't work very well
before. And it's not batching the commits better; it's reducing the
lock contention around realizing that the batched commit has happened.
>> I updated the release docs to call the item "group commit" because I now
>> don't see any reference to that term in our docs.
>
> I don't think I'd mention WAL writing at all, and just say that it
> improves the concurrency of locking around group commits.
+1.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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