I'm in progress of preparing this page
http://www.sai.msu.su/~megera/wiki/rbtree_test
Hope, tests are easy to reproduce.
This is slightly improved version of rbtree patch, Teodor didn't commit yet.
Random array test and real-life examples are ok, I still working on
test #1, which is quite artificial test, but still I want to understand if
the results are in accuracy of test.
Oleg
On Thu, 4 Feb 2010, Mark Cave-Ayland wrote:
Robert Haas wrote:
Maybe we are now getting to the heart of the confusion. Mark wrote in
his email: "Unfortunately I was not really able to reproduce the RND
(teodor's) dataset, nor the random array test as the SQL used to test
the implementation was not present on the page above." The SQL for
the fixed-length tests is posted, but the SQL for the variable length
test is not - so Mark was just guessing on that one.
Or am I just totally confused?
...Robert
No, that's correct. In the "Repeat test with 100,000 identical records
varying array length (len)" section, it's fairly easy to substitute in the
varying values of len where len = 3, 30 and 50. As documented in my review
email I had a guess at generating the contents of RND (teodor's) column with
this query:
select ARRAY(select generate_series(1, (random() * 100)::int)) as arand into
arrrand from generate_series(1,100000) b;
However, unlike the other figures this is quite a bit different from
Oleg/Teodor's results which make me think this is the wrong query (3.5s v
9s). Obviously Robert's concern here is that it is this column that shows one
of the largest performance decreases compared to head.
I've also finished benchmarking the index creation scripts yesterday on
Oleg's test dataset from
http://www.sai.msu.su/~megera/postgres/files/links2.sql.gz. With
maintenance_work_mem set to 256Mb, the times I got with the rbtree patch
applied were:
rbtest=# CREATE INDEX idin_rbtree_idx ON links2 USING gin (idin);
CREATE INDEX
Time: 1910741.352 ms
rbtest=# CREATE INDEX idout_rbtree_idx ON links2 USING gin (idout);
CREATE INDEX
Time: 1647609.300 ms
Without the patch applied, I ended up having to shutdown my laptop after
around 90 mins before the first index had even been created. So there is a
definite order of magnitude speed increase with this patch applied.
ATB,
Mark.
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: o...@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
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