From: Mikheev, Vadim <vmikheev@SECTORBASE.COM>
To: 'Matthias Urlichs' <smurf@noris.de>
To: Hannu Krosing <hannu@tm.ee>
Cc: Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>
Cc: 'Michael A. Olson' <mao@sleepycat.com>
Cc: 'pgsql-hackers@postgreSQL.org' <pgsql-hackers@postgresql.org>
Subject: RE: Berkeley DB...
Date: Thu, 25 May 2000 09:09:26 -0700
Message-ID: <8F4C99C66D04D4118F580090272A7A23018C01@SECTORBASE1> (raw)
> Times for the insert loop:
> 14 MySQL-MyISAM
> 23 PostgreSQL (no fsync)
> 53 MySQL-BDB (with fsync -- don't know how to turn it off yet)
PostgreSQL 6.5.3; -B 16384; SUN Ultra10 with some IDE disk.
1. with fsync, all inserts in single transaction: 73 sec
2. with fsync, use COPY: 3 sec
3. without fsync, use COPY: 3 sec
4. without fsync, all inserts in single transaction: 71 sec
5. without fsync, each insert in own transaction: 150 sec
Do you see difference for INSERT/COPY in 1./2.? Shouldn't we try
to speed up our PARSER/PLANNER, keeping in mind that WAL will speed
up our storage sub-system?!
Also, 4. & 5. show that transaction begin/commit take too long time.
Could you run your test for all inserts in single transaction?
(If we want to test storage sub-system, let's do our test un-affected
by other ones...)
> The select:
> 0.75 MySQL-MyISAM
> 0.77 MySQL-BDB
> 2.43 PostgreSQL
select a from foo order by a
didn't use index in my case, so I've run
select a from foo where a >= 0 also.
1. ORDER: 0.74
2. A >= 0 with index: 0.73
3. A >= 0 without index: 0.56
Note that I used -B 16384 (very big pool) and run queries *twice* to get
all data into pool. What size of pool did you use? 64 (default) * 8192 =
512Kb,
but size of foo is 1.5Mb...
2. & 3. show that index slows data retrieval... as it should -:)
Also, does MySQL read table itself if it can get all required
columns from index?! I mean - did your query really read *both*
index and *table*?
PostgreSQL has to read table anyway...
Vadim
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To: pgsql-hackers@postgresql.org
Cc: vmikheev@SECTORBASE.COM, smurf@noris.de, hannu@tm.ee, ZeugswetterA@wien.spardat.at, mao@sleepycat.com
Subject: RE: Berkeley DB...
In-Reply-To: <8F4C99C66D04D4118F580090272A7A23018C01@SECTORBASE1>
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