[9.3 CF 1] 2 Weeks In & The problem with Performance Patches

Folks,

We are starting the 3rd week of the commitfest tommorrow, and here's the
update on status. In the last week, we are at the following status levels:

- 40 patches still Need Review,
including 11 which have no reviewer assigned.
- 23 patches are Waiting on Author, most of them
because they are still under discussion on this list.
- 17 patches are marked Ready for Committer,
including 10 of the 11 regression tests*
- 17 patches have been Committed
- 9 patches have been Returned with Feedback
- 1 patch has been Rejected

(* the tests actually need a test of the cumulative total time to run,
which I'll be working on today)

At current commit/return rates, this commifest will finish around July 28th.

What seems prepared to drag out this commitfest possibly beyond the end
of July are the several performance optimization patches, which include:

- Remove PD_ALL_VISIBLE**
- Improvement of checkpoint IO scheduler for stable transaction responses
- Use posix_fallocate to build (new) WAL files**
- Performance Improvement by reducing WAL for Update Operation**
- GIN improvements (4 patches)**
- XLogInsert scaling

Items marked ** are waiting on review.

The problem with these patches is that (a) people feel reluctant to
review them, since not too many hackers feel qualified to review
performance, and (b) the review will need to include performance
testing, which will make it take longer and likely bottleneck on
qualified testers.

So, two things:
(1) if you are qualified to review any of the above, please get started
*now*, and leave the non-performance patches for later;
(2) ideas on how we can speed up/parallelize performance testing efforts
are extremely welcome.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com