Question

I know index increase the select query but slows down the insert query because every time the data is inserted the indexes are also updated.

I need to use all the queries insert/update/delete/select in my useraccount table.

Now I want to know Should I use index .If yes,then please tell me some ways to speed up insert query while using index

Answer 1

You should use index every time where the benefits of faster queries are convincingly greater than the disadvantages of slower inserts, updates and deletes. Use queries on columns that are frequently used in WHERE conditions.
If you have mass inserts, you might want to drop/disable/unuse the index(es) and rebuild them after the action.