Effects of order of columns, while defining an index on them, on the performance of the queries
- by Hossein
Hi,
Does order of the columns in an Index definition for a table in a database has any effect on the performance?
for e.g. are these two queries different ?
CREATE INDEX xxx ON tablex(col1,col2)
CREATE INDEX xxx ON tablex(col2,col1)
what about the in case that I use a BTREE index?
I am using Mysql.
thanks
