Create Index (SQL)
The syntax for creating an index is:
CREATE [UNIQUE] INDEX index_name ON table_name (column1, column2, ... column_n)
UNIQUE indicates that the combination of values in the indexed columns must be unique.
CREATE INDEX customer_idx ON customer (customer_name);
In this example, an index has been created on the customer table called customer_idx. It consists of only of the customer_name field.
The following creates an index with more than one field:
CREATE INDEX customer_idx ON supplier (customer_name, country);
Content extracted from free documentation (Wikipedia and other sources).