Creating A MySQL Composite Index
An index can be created in one or more columns. IF the number of columns included in an index is greater than one it’s known as a: Composite index
An index created on multiple table data columns is called a composite index as shown in Diagram 1.
The following is the syntax for creating composite index.
<System prompt> CREATE INDEX <IndexName> ON <Table Name> (<Column Name1>, <Column Name2>);
mysql> CREATE INDEX product_id ON productdetail (Serial_NO, ID);