What is the use of truncate in MySQL?

Why truncate is used?

Typically, TRUNCATE TABLE quickly deletes all records in a table by deallocating the data pages used by the table. This reduces the resource overhead of logging the deletions, as well as the number of locks acquired. Records removed this way cannot be restored in a rollback operation.

Why truncate is used in SQL?

TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. Fewer locks are typically used. When the DELETE statement is executed using a row lock, each row in the table is locked for deletion.

Should I use truncate or delete?

In the TRUNCATE command, the transaction log for each deleted data page is recorded. Unlike the DELETE command, the TRUNCATE command is fast. We cannot rollback the data after using the TRUNCATE command.

Difference between DELETE and TRUNCATE.

S.NO Delete Truncate
9. The delete can be used with indexed views. Truncate cannot be used with indexed views.

What is difference between delete and truncate in MySQL?

Delete and truncate both commands can be used to delete data of the table. Delete is a DML command whereas truncate is DDL command. Truncate can be used to delete the entire data of the table without maintaining the integrity of the table.

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What are 2 differences between delete and TRUNCATE?

Delete vs Truncate

SQL Delete SQL Truncate
It removes rows one at a time. It removes all rows in a table by deallocating the pages that are used to store the table data
It retains the identity and does not reset it to the seed value. Truncate command reset the identity to its seed value.

Which is faster delete or TRUNCATE?

TRUNCATE is faster than DELETE , as it doesn’t scan every record before removing it. TRUNCATE TABLE locks the whole table to remove data from a table; thus, this command also uses less transaction space than DELETE .

Can you TRUNCATE a column in SQL?

What is the Truncate Command in SQL? We use the Truncate command to delete the data stored in the table. The working of truncate command is similar to the working of Delete command without a where clause.

Does TRUNCATE free space?

Truncating a table does not give any free space back to the disk – you need to run a SHRINKDATABASE operation for the allocated space to be successfully de-allocated and returned to the disk. Also, as others have mentioned, maybe the table was not taking up much space in the first place.

Is TRUNCATE a DDL command?

Although TRUNCATE TABLE is similar to DELETE , it is classified as a DDL statement rather than a DML statement. It differs from DELETE in the following ways: Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly for large tables.

What is difference between stored procedure and function?

The function must return a value but in Stored Procedure it is optional. Even a procedure can return zero or n values. Functions can have only input parameters for it whereas Procedures can have input or output parameters. Functions can be called from Procedure whereas Procedures cannot be called from a Function.

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What is difference between DDL and DML?

DDL stands for Data Definition Language. DML stands for Data Manipulation Language. DDL statements are used to create database, schema, constraints, users, tables etc. DML statement is used to insert, update or delete the records.

Are DML commands Autocommit?

No. Only the DDL(Data Definition Language )statements like create,alter,drop,truncate are auto commit.

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