Showing posts with label delete. Show all posts
Showing posts with label delete. Show all posts

Friday, July 29, 2011

Difference between Delete and Truncate in SQL Server

Delete vs Truncate
 
Delete

  • Delete command removes the rows from a table based on the condition that we provide with a WHERE clause
  • DELETE removes rows one at a time and records an entry in the transaction log for each deleted row.
  • DELETE does not reset identity of the table. So, if you want to retain the identity counter, use DELETE.
  • DELETE Activates Triggers.
  • DELETE Can be Rolled back.
  • DELETE is DML Command.
Truncate
  • Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command.
  • TRUNCATE removes the data by de-allocating the data pages used to store the table’s data, and only the page de-allocations are recorded in the transaction log.
  • TRUNCATE Resets identity of the table.
  • Because TRUNCATE TABLE is not logged, it cannot activate a trigger.
  • TRUNCATE can not be Rolled back.
  • Truncate is a DDL Command.
  • You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY constraint.