using temporary in the output of
explain always bad?
To give an example, I have a three-way join on three very large tables. The indexes are correct. The columns being joined on are indexed and have matching column lengths. The only red flag is
using temporary. Is this simply unavoidable given the circumstances?
These are in-memory temp tables, not disk tables, so I'm thinking, maybe it's just how MySQL works, and not always a bad thing. (To give a sense of size... the row product is
1300 x 1 x 3).