Hey, I have a script that caches the output from a query, but whenever the query is run my cpu usage jumps to like 25%

the query (theres about 5 different queries similar to this) is

select n.name, ifnull(c.kills_d,0)+ifnull(s.kills_d,0)+ifnull(r.kills_d,0)+ifnull(k.kills_d,0)+ifnull(o.kills_d,0)  scores, c.online_d+s.online_d+r.online_d+k.online_d+o.online_d online_d from names n
	 left join scores_ctf c on n.id=c.name
	left join scores_slayer s on n.id=s.name
	left join scores_race r on n.id=r.name
	left join scores_king k on n.id=k.name
	left join scores_oddball o on n.id=o.name where n.common=0 order by 2 desc, n.name limit 1;

Basically I need the max combined of a column from 5 different tables, and each entry is not guaranteed to be in every table. I tried creating indexes on the columns, but im not too familiar with index optimization.. can anyone give me some pointers?

Make sure you are joining on PK's. Since you check common=0 I'd put an index on that column too.

Additional option could be to create a view to hold all the information, so you could query the view instead of all the tables.