How to know which index is used during the execution of sql

sangiah · Active User Joined: 10 Jun 2005 Posts: 63

dbaprasad · New User Joined: 06 Jun 2005 Posts: 3 Location: pune

issue EXPLAIN command,

Smitha · New User Joined: 20 Jun 2005 Posts: 5

Hi,

During the execution of an SQL, if the WHERE clause contains any of the fields that is in the index, then it will use that particular index.

Suppose you have 2 indexes: X1: A,B
X2: Y,Z
Now your WHERE clause has the field B, then the first index will be used.

Indexes are used to improve the peformance of your query.

-Smitha.