MySQL and Index

[clarissa1996]

I have craeted a table with 2 columns (col1 and col2).
Then I have created 2 indexes (one for col1 and one for col2).

The following queries are very fast:

SELECT * FROM table WHERE col1='...';
SELECT * FROM table WHERE col2='...';
SELECT * FROM table WHERE col1='...' AND col2='...';

But if I replace "AND" with "OR":

SELECT * FROM table WHERE col1='...' OR col2='...';

the query is NOT fast !!

Here is my question:
If I make a query with an OR clause, indexes are not used ?
Is there a solution ?

Thanks for any help. Michelangelo

 

[piti]

read this

http://www.mysql.com/documentation/mysql/bychapter/manual_MySQL_Optimisation.html#MySQL_indexes,

there is explained the use of indexes