delete and truncate difference sql

Differences between the SQL Server DELETE and TRUNCATE Commands

• Truncate reseeds identity values, whereas delete doesn't.
• Truncate removes all records and doesn't fire triggers.
• Truncate is faster compared to delete as it makes less use of the transaction log.

1. Which is faster delete or truncate in SQL?
2. Why use truncate instead of delete?
3. What is difference between delete and drop?
4. What does truncate mean in SQL?
5. Which is better truncate or delete?
6. Is truncate faster than drop?
7. Can we rollback delete and truncate?
8. Why truncate is DDL and Delete is DML?
9. Does truncate free space?
10. Is Grant DDL or DML?
11. What is Delete command?
12. Can we rollback truncate?

Which is faster delete or truncate in SQL?

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 .

Why use truncate instead of delete?

TRUNCATE TABLE is faster and uses fewer system resources than DELETE , because DELETE scans the table to generate a count of rows that were affected then delete the rows one by one and records an entry in the database log for each deleted row, while TRUNCATE TABLE just delete all the rows without providing any ...

What is difference between delete and drop?

DELETE is a Data Manipulation Language command, DML command and is used to remove tuples/records from a relation/table. Whereas DROP is a Data Definition Language, DDL command and is used to remove named elements of schema like relations/table, constraints or entire schema.

What does truncate mean in SQL?

TRUNCATE TABLE removes all rows from a table, but the table structure and its columns, constraints, indexes, and so on remain. To remove the table definition in addition to its data, use the DROP TABLE statement.

Which is better truncate or delete?

Truncate is faster compared to delete as it makes less use of the transaction log. Truncate is not possible when a table is referenced by a Foreign Key or tables are used in replication or with indexed views.

Is truncate faster than drop?

The TRUNCATE command is faster than both the DROP and the DELETE command. Like the DROP command we also can't rollback the data after using the this command.

Can we rollback delete and truncate?

The operation cannot be rolled back. DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.

Why truncate is DDL and Delete is DML?

Although TRUNCATE TABLE is similar to DELETE , it is classified as a DDL statement rather than a DML statement. ... Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly for large tables. Truncate operations cause an implicit commit, and so cannot be rolled back.

Does truncate free space?

If you're using innodb_file_per_table=ON, or you're using MyISAM, TRUNCATE TABLE will delete the table files used by the table in question (and create new, empty ones). So, the space used will be released to the file system, and in Unix/Linux, “df” on the file system will show new space.

Is Grant DDL or DML?

Data Definition Language (DDL) Statements

Create, alter, and drop schema objects. Grant and revoke privileges and roles.

What is Delete command?

The delete command is used to remove data that is no longer required from a table. The "WHERE clause" is used to limit the number of rows affected by the DELETE query.

Can we rollback truncate?

You cannot ROLLBACK TRUNCATE

Simply, you cannot rollback a transaction if it is already committed but you can do something else to get the data back (or at least some parts of it). When you execute the TRUNCATE statement, your data is still in the MDF file.