key_buffer is 384M, table1.MYI is 17.5MB. Jeremy Zawodny wrote:
>On Mon, Mar 18, 2002 at 11:39:09AM -0500, Gabriel Ricard wrote: > >>Greetings, >> >>We're running MySQL 3.23.47 on MacOS X 10.1.2. We've got a rather large >>table ( 200,000+ records, 120+ columns) and some simple queries on that >>table have pretty inconsistent performance. Due to licensing issues I >>can't give an actual example of the table, but here is an equivalent >>example: >> >>Field1 and Field2 are both unsigned integers >>IndexField1 is an unsigned integer and is the primary key >> >>select Field1,Field2 from table1 where IndexField1 = 345232; >> >>We ran this query will different values for IndexField1, sometimes it >>would return in around 0.01 seconds, other times it would take as long >>as 9 seconds. There was no other load on the database when this was >>occurring, and it was specific to certain records (one IndexField1 would >>always return around 8 seconds, others would always return around 0.01 >>seconds). >> >>Is there any kind of reasonable explanation for this behavior? Is it >>perhaps because of where the records are situated on the hard disk (seek >>times)? Is it maybe a caching issue? >> > >How large is the index file? And how large is you key buffer? If >your key buffer is too small, you could see variable performance on >index-based lookups. > >Jeremy > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
