Re: MySQL can't find index = really slow query...

[Alessio Pianigiani]

I simpy pasted your query, and the EXPLAIN command gave me those results:


id,"select_type","table","type","possible_keys","key","key_len","ref","rows","Extra"
1,"SIMPLE","p","const","PRIMARY","PRIMARY","4","const",1,""
1,"SIMPLE","d","const","PRIMARY","PRIMARY","4","const",1,""
1,"SIMPLE","c","const","PRIMARY","PRIMARY","2","const",1,""
1,"SIMPLE","pr","const","PRIMARY,provincia_ID","PRIMARY","2","const",1,""
1,"SIMPLE","r","const","PRIMARY,regione_ID","PRIMARY","2","const",1,""
1,"SIMPLE","a","ALL","","","","",88339,"Using where"
1,"SIMPLE","n","ALL","","","","",91010,"Using where"

Is your pruposed query just a better formed query, or it's also a better performing one?