Quote:
In SQL, Index performs my Update or not ?
That question makes no sense at all. Indexes do not "perform any updates". Not in the sense you're using the terminology anyway.
If the id is a primary key column, the key column is already going to be indexed. There's no way to speed that up to any significant degree.
If it's not a primary key, then you can add an index to the table for that column. That will speed up searches in your "id" column dramatically.
But, you never get anything for free. When you INSERT records into the table, the index also has to be updated, so there's a performance hit on every INSERT. If you happen to update the "id" value, that's also going to trigger an update to the index.
Without the index, your statement has to do what's called a "table scan". It has to look at every row in the table, checking the '9000' against the id column in every row, looking for matches. On a million records, that's going to take quite a long time.