comparison of truncate vs delete in mysql/sqlserver

comparison of truncate vs delete in mysql/sqlserver [duplicate]

 

DELETE

1. DELETE is a DML Command.
2. DELETE statement is executed using a row lock, each row in the table is locked for deletion.
3. We can specify filters in where clause
4. It deletes specified data if where condition exists.
5. Delete activates a trigger because the operation are logged individually.
6. Slower than truncate because, it keeps logs.
7. Rollback is possible.

TRUNCATE

1. TRUNCATE is a DDL command.
2. TRUNCATE TABLE always locks the table and page but not each row.
3. Cannot use Where Condition.
4. It Removes all the data.
5. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions.
6. Faster in performance wise, because it doesn't keep any logs.
7. Rollback is possible.

 

• DELETE and TRUNCATE both can be rolled back when used with TRANSACTION (TRUNCATE can be rolled back in SQL Server, but not in MySQL).
• if there is a PK with auto increment, truncate will reset the counter

http://beginner-sql-tutorial.com/sql-delete-statement.htm

 

作者:Chuck Lu    GitHub