Home/ Questions/Q 813117
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-15T01:18:31+00:00

This query was working fine when the database was small, but now that there

  • 0

This query was working fine when the database was small, but now that there are millions of rows in the database, I am realizing I should have looked at optimizing this earlier. It is looking at over 600,000 rows and is Using where; Using temporary; Using filesort (which leads to an execution time of 5-10 seconds). It is using an index on the field ‘battle_type.’

SELECT username, SUM( outcome ) AS wins, COUNT( * ) - SUM( outcome ) AS losses
FROM tblBattleHistory
WHERE battle_type =  '0' && outcome <  '2'
GROUP BY username
ORDER BY wins DESC , losses ASC , username ASC 
LIMIT 0 , 50
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    First thing would be to make sure you have good indexes (as others have mentioned).

    However, it looks like you’re creating a leaderboard of some sort for a web page. My first question would be – do you really need to execute this query in real time? Could you create a table in your database (or add a wins and losses column to the users table) with the results of this query and simply refresh it periodically?

    • 0