In the last episode (Mar 26), Kyle Renfro said: > I am testing MySQL as a possible replacement for our proprietary db > server for several large databases. I really want MySQL but I am > getting what seems like slow search times. > > Does 6.5 seconds seem slow/typical/fast for the following search? > > SELECT main.ownername FROM main, rolledplate WHERE rolledplate.platenum > LIKE '3^6SP%' AND main.recid = rolledplate.recid; > > The 'main' table has 21+ million records. The 'rolledplate' table has > 144+ million records. > > The EXPLAIN gives pretty optimal results and I have tried the select > syntax several different ways. The recid field is the PK in the main > table. In both tables RECID is an unsigned int with a 1:M > relationship between main and rolledplate. The tables are MyISAM > with a fixed row format.
What's the EXPLAIN look like, and how many records do you get from the above query: total, and average per rollplate.recid (i.e what's M)? 6 seconds could be high if you are returning only a couple of records, but if you're returning over 600 records, than it's reasonable (assuming slow disks at 100 seeks/sec). Since you're only fetching one field, creating multicolumn indexes on rolledplate (platenum, recid) and main (recid, ownername) may let you avoid table lookups altogether. -- Dan Nelson [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]