1)DELETE-Delete command is using to remove a rows from a table.
“Where” clause is used to remove some rows.
if no “where” condition specified all rows will be removed.
After performing a DELETE operation you need to “commit” or “Rollback” the transaction to make the change permanent or undo it.
2)TRUNCATE- “truncate” removes all rows from a table
this operaion cannot be rolled back and no triggers will be fired
truncate is faster than delete and doesnt use as much undo space as delete.
3)DROP- removes a table from the database
All the tables rows,indexes and privileges will also be removed.
this operation cannot be rolled back.