trupti11

 Profile Answers by trupti11 

• Nov 14th, 2010

 

There are a couple of reasons that I can think of for this:
(1)  The indexes that are created on a table occupy physical disc space, the more the number of indexes created, the more would be the storage space occupied.
(2)  The indexes slow down the DML operations such as insertion, deletion, and updation, the database needs to update all of the indexes where data has changed.
Indexing can help the database during data modification statements by allowing the database to quickly locate the records to modify, however, we now caveat the discussion with the understanding that providing too many indexes to update can actually hurt the performance of data modifications. This leads to a delicate balancing act when tuning the database for performance.

Hence, the more number of indexes is prohobited in systems with large data manipulations, however, we can use indexes in databases that are used majorly for reporting purposes.