speeding up a query on MySql I have a table with more than 10 million rows and 10 fields(columns). There is an index on field_1 and I am running the following query.

create table t2 
select field_1,
       sum(ifnull(field_2,0)) as field_2, 
       sum(ifnull(field_3,0)) as field_3,
       sum(ifnull(field_4,0)) as field_4 
from t1 
group by field1;


The data type of all the columns is varchar(200).

This query is not able to produce the result even after running for more than 1 day. Any suggestions on getting the results quickly will be helpful.
Here's what I'd do:


Use EXPLAIN on your SELECT to reveal which indexes it's using. 
Tune your query and repeat step 1 until satisfied. 
Create your new table with the desired structure.
Use INSERT ... INTO new table SELECT FROM ... old table replacing the select part with the SELECT query you tuned in step 2.