Hello mysql,
I made one more test of mysql perfomance.
PIII-700/768Mb/Linux 2.4.2 glbc 2.1.3
I had the followings table with 12.000.000 rows (well I checked
this with 10000 rows as well but the speed does not differs much)
in it and I checked how fast I can select data by hash key "select *
from g00pages where hash=1" - the query was constant and only one
row matched. The speed was about queries/sec 1800.
So I decided to check what about selecting many pages at the time.
like "select * from g00pages there hash in (1,2,3...)" - the best
result I got is then selecting about 100 pages/query this gave me
about 2 times more perfomance then selecting pages one by one. This
locked even more upsetting.
I've tried the same thing with heap table - the result's are
strange. The perfomance is starting from about 3600 pages/sec then
I've increased The number of pages/query I've got up to 70000
pages/sec which is quite good :)
The strange thing is why result differ so much then ALL data fits it
memory without any problem
Well. Of couse I'll soon try glibc 2.2.x with your patches but I
don't se how it can improve things then I have obly one thread
running and one cpu and the query is running relatively big.
Heikki made tests which also shows some strange things - for
example why INSERT is FASTER then SELECT.
Even looking at the context swithces does not explain the thing much
- my result show that this system can do about 300.000 of context
swithces per second - so 5.000-10.000 of context swithces per second
does not eat much from cpu.
This is the table structure.
CREATE TABLE g00pages (
page_id int(10) unsigned NOT NULL auto_increment,
page_prot tinyint(3) unsigned NOT NULL default '0',
page_domain int(10) unsigned NOT NULL default '0',
page varchar(255) NOT NULL default '',
TS timestamp(14) NOT NULL,
LCHECKED timestamp(14) NOT NULL,
RETRY tinyint(3) unsigned NOT NULL default '0',
UPDATED timestamp(14) NOT NULL,
SIZE int(10) unsigned NOT NULL default '0',
TITLE varchar(100) NOT NULL default '',
port smallint(5) unsigned NOT NULL default '0',
QUERY varchar(255) NOT NULL default '0',
hash int(10) unsigned NOT NULL default '0',
PRIMARY KEY (page_id),
KEY hash (hash)
) TYPE=MyISAM PACK_KEYS=1;
--
Best regards,
Peter mailto:[EMAIL PROTECTED]
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