Thread

Re: WIP: Fast GiST index build

Alexander Korotkov <aekorotkov@gmail.com> — 2011-08-02T12:33:16Z

Hi!

I'm now working on adding features to your version of patch. Current version
is attached. Somehow this version produce huge amount of WAL and that makes
it slow. Though count and avg. length of WAL records is similar to that of
non-buffering build.

test=# create table points as (select point(random(),random()) from
generate_series(1,1000000));
SELECT 1000000
test=# select pg_xlogfile_name_offset(pg_current_xlog_location());
       pg_xlogfile_name_offset
-------------------------------------
 (000000010000004000000073,15005048)
(1 row)

test=# create index points_idx on points using gist (point) with
(buffering=off);CREATE INDEX
test=# select pg_xlogfile_name_offset(pg_current_xlog_location());
       pg_xlogfile_name_offset
-------------------------------------
 (00000001000000400000007E,13764024)
 (1 row)

test=# create index points_idx2 on points using gist (point) with
(buffering=on, neighborrelocation=off);
INFO:  Level step = 1, pagesPerBuffer = 406
NOTICE:  final emptying
NOTICE:  final emptying
NOTICE:  final emptying
NOTICE:  final emptying
CREATE INDEX
test=# select pg_xlogfile_name_offset(pg_current_xlog_location());
       pg_xlogfile_name_offset
-------------------------------------
 (0000000100000040000000D2,10982288)
(1 row)

May be you have any ideas about it?

------
With best regards,
Alexander Korotkov.