I am reading DBMS concepts and i have some confusion about TRUNCATE and DROP. I know TRUNCATE does not affect structure, but what are other differences? When its better to use TRUNCATE and when DROP is better?
In some website it is written that truncate is faster but no one explained why.
There is lots of information available on the difference of both ( see here). However for the second part of your question regarding the performance - you should not worry that much for truncate vs drop. The reason being is it's more about the functionality you are expecting from truncate vs drop. You 'drop' when you don't intend to use the table anymore. You 'truncate' when you just want the table definition intact , you just want to delete the table data fast. The perceived difference in performance may come from the implementation details ( which can sometime be a bug like this) in the database.