Peter Lauri wrote: > Best group member, > > > > Assume that I save data about an object and it has 10.000 observations of > the object stored in a MySQL database. I want calculate the average value > of a column, is it faster done by using PHP on the result array or using > the MySQL function to do that? > > > > /Peter Hands down it will be the SQL database. To do an average, you must retrieve all the data from disk anyway, that's your big hit, the summing all the columns and dividing by the count is trivial compared to sending all that data to a PHP box to do the average. You would be better off all together figuring out how to not hit all those records each time and keep a running average. Something like: $total_sum += $new_entry; $count ++; $avg = $total_sum/$count; You will have to keep track of count and total_sum in some mutex locked type of methodology, but any lock contention you get from it will almost certainly out perform getting 10,000 records from a database. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
