I'm converting a PHP app from using Visual FoxPro as the database backend to using MySQL as the backend. I'm testing on MySQL 4.1.22 on Mac OSX 10.4. The end application will be deployed cross platform and to both 4.x and 5.x MySQL servers.
This query returned 21 records in .27 seconds. SELECT zip FROM zipcodes WHERE degrees(acos(sin(radians(39.0788994))*sin(radians(latitude))+ cos(radians(39.0788994))*cos(radians(latitude))*cos(radians(-77.1227036-longitude))))*60*1.1515 < 5 This query returned 21442 records in 1.08 seconds. SELECT custzip FROM customers This query is still running half an hour later, with a Time of 2167 and a State of "Sending Data" (according to the mysql process list) SELECT custzip FROM customers WHERE custzip IN (SELECT zip FROM zipcodes WHERE degrees(acos(sin(radians(39.0788994))*sin(radians(latitude))+ cos(radians(39.0788994))*cos(radians(latitude))*cos(radians(-77.1227036-longitude))))*60*1.1515 < 5) When I try to EXPLAIN the query it gives me the following... id,select_type,table,type,possible_keys,key,key_len,ref,rows,Extra 1,PRIMARY,customers,index,NULL,cw_custzip,30,NULL,21226,Using where; Using index 2,DEPENDENT SUBQUERY,zipcodes,ALL,NULL,NULL,NULL,NULL,42144,Using where If it matters both tables are INNODB and both customers.custzip and zipcodes.zip are indexed. We used a program called DBConvert from DMSoft to convert the data so it's "exactly" the same on both the VFP side and the MySQL side. With all that in mind... VFP returns the exact same query in 5-10 seconds and that includes render time in the web browser. By comparison... the query WHERE id IN (SELECT id FROM phone WHERE phonedate >= '2001-01-01' AND phonedate <= '2009-06-18') returns almost instantly. I'm at a complete loss... The suggestions I've seen online for optimizing Dependent Subquery's basically revolve around changing it from a sub-query to a join but that would require more re-architecturing than I want to do... (Unless I'm forced) Especially since more than a few of those solutions suggested precalculating the distance between zipcodes which only works if the distances are known (only allow 10, 50 and 100 mile radi for example) Any ideas? Thanks in advance! Matt -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org