In t sql what is the difference between truncate and delete

Thus, the trgdeletestudent trigger did not fire. Then, execute the following insert query to add records to the tblStudent the table:. Run the following query to grant access to testuser1 on the tblStudent table:. CodingSight is open for new authors and partnership proposals. Send your offers and ideas to marketing devart. Search Menu. This article will focus on these differences and illustrate them with practical examples.

Resets the identity value. Does not reset the identity value. Is faster due to minimal usage of the transaction log. So I often start with a question like "What is the difference between Delete and Truncate? To my surprise, I have heard many shocking answers. One candidate told me truncate will delete the entire schema and all tables. I said what? And what about DROP? Is that true, even if we start a transaction? Now we have a table with dummy records.

Run the below command and see what you get:. Try on your own and let me know if you experience any issues. Imran, Your point is valid. Most of the sites and even microsoft says Truncate cannot be rolled back but in real if you start under transaction it can be rolled back like delete statement.

Let me know if you still have any queries. Roger: It will last till checkpoint And will be part of your Transaction log backup which help you to recover DB to a specific point in time. We can see the deleted record gets a rollback and we can see it in the Employee table. It removes all rows in a table. SQL Server stores data of a table in the pages. The truncate command deletes rows by deallocating the pages. It makes an entry for the de-allocation of pages in the transaction log.

It does not log each row deletion in the transaction log. We cannot specify any condition in the SQL Truncate command. At a high level, you can consider truncate command similar to a Delete command without a Where clause.

It locks the table and the pages instead of a row. In the following screenshot, you can see the estimated execution plan.

The SQL truncate command is straightforward; you just need to pass the table name to remove all rows. In the previous example 3, we explored delete command with the identity values. Delete does not reset identity values. In example 4, w explored to roll back a transaction with the delete command. Is it true? Now, issue the Rollback Tran command and verify the records in the table.

We get our data back in the table. It shows that we can roll back delete as well as truncated command started within a transaction. Delete command is useful to delete all or specific rows from a table specified using a Where clause.

It removes all rows in a table by deallocating the pages that are used to store the table data. Truncate deallocates all data pages of a table.