Hi all.

Almost all the beginners/experts will atleast confuse a little bit while answering this question.
Similarly I had it a long time back.

Truncate is a DDL command and Delete is a DML command.

After execution of DDL statements commit performs implicitly. That is why your changes are committed automatically when ever you perform a DDL statement ( Create,Alter,Drop,Truncate,rename, etc).

DML statements does not commit your changes. You have to commit explicitly inorder to save your changes. Examples of DML commands are select, insert, update, Delete etc.

Simply to say - DML statements can be rollbacked where DDL are autocommit.

Please share if you have any inputs also....

TRUNCATE is faster as it is a DDL statement and no rollback segment needed.
And data cannot be retrieved in normal conditions since DDL has no explicit commit is required.

DELETE is a bit slower as it is a DML Statement and rollback segment is required.
Selective data can be deleted using where condition and commit needs to be done to complete the transaction.

Deleting a table is logged operation, so the deletion of each row gets logged in the transaction log, which makes it slow.

Truncate table also deletes all the rows in a table, but it won’t log the deletion of each row, instead it logs the de-allocation of the data pages of the table, which makes it faster.

And we need to remember all the time, that Truncat[e]'ing a table can't be rolled back.

There is one more difference between these two -

TRUNCATE command resets the High Water Mark for the table but DELETE does not.
So TRUNCATE operations on table are much faster.