Hi,
Every table by default have a Prinmary index based on the Primery keys.
Means when you wants to fetch data , it is easily fetched using that primary Index(based on primary keys).
Some time we may need to fetch data from the tables by using other fields which are not key fields. Then in that case to fetch the data fast we have to create the seconday indexes , so that the data is fetched fast using that Index.
Regards,
Anji
