Hello, thanks for your fast reply. even when i use EXPLAIN SELECT * FROM `actions` ORDER BY datum LIMIT 10 the key isn't used. the query takes about 2s :-(
Corin Tuesday, December 9, 2003, 10:19:16 AM, you wrote: MT> Hi, MT> I'm not saying I fully understand the MySQL optimizer, as MT> I never had to deal with it before... but: MT> Why should it use an index if the statement is returning ALL MT> rows? It might be faster to read them into memory ( 75853 MT> isn't really much ) and sort them there instead of moving the MT> diskhead back and forth between the index and the data. >> i'm having a problem with mysql. when i put an index on a >> datetime column, it's never used. >> >> for example the >> sql: 'EXPLAIN SELECT * FROM actions ORDER BY datum' >> >> shows: >> table type possible_keys key key_len ref rows Extra >> actions ALL NULL NULL NULL NULL 75853 Using filesort >> >> even if i use the >> sql: 'EXPLAIN SELECT * FROM actions USE INDEX (datum) ORDER BY datum' >> >> mysql doesn' use the index :-(( MT> With regards, MT> Martijn Tonies MT> Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL MT> Server. MT> Upscene Productions MT> http://www.upscene.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
