What is the use of truncate in MySQL?
TRUNCATE TABLE empties a table completely. It requires the DROP privilege. Logically, TRUNCATE TABLE is similar to a DELETE statement that deletes all rows, or a sequence of DROP TABLE and CREATE TABLE statements. To achieve high performance, TRUNCATE TABLE bypasses the DML method of deleting data.
What is the purpose of truncate command?
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.
What is difference between DELETE and truncate in MySQL?
DELETE is a SQL command that removes one or multiple rows from a table using conditions. TRUNCATE is a SQL command that removes all the rows from a table without using any condition. It is a DML(Data Manipulation Language) command.
Why is TRUNCATE a DDL command?
TRUNCATE resets the high water mark of the table, effectively eliminating all the previously existing rows. Treating it as a DDL statement allows it to be super-fast, as it allows it to function without retaining undo (rollback) information like DML statements.
What is TRUNCATE function in SQL?
The SQL TRUNCATE TABLE statement is used to remove all records from a table. It performs the same function as a DELETE statement without a WHERE clause.
What is difference between DROP and TRUNCATE?
In SQL, the DROP command is used to remove the whole database or table indexes, data, and more. Whereas the TRUNCATE command is used to remove all the rows from the table.
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.
What is difference between TRUNCATE and drop statement?
Does TRUNCATE drop and recreate table?
TRUNCATE TABLE is similar to DELETE , but this operation is a DDL (Data Definition Language) command. It also deletes records from a table without removing table structure, but it doesn’t use the WHERE clause.
What is use of TRUNCATE in SQL?
The TRUNCATE TABLE command deletes the data inside a table, but not the table itself.
How do you TRUNCATE a database?
Select Database -> More Database Operations -> Truncate Database (Shift+Del) to truncate (make the tables empty) all the tables of a database (however, the Tables and other objects (Stored Procedures, Views etc.) are not dropped).
Why is truncate faster than deleted in SQL?
What is difference between truncate and delete? Answer : This is most important interview question.
Is truncate faster or delete?
TRUNCATE is faster than DELETE due to the way TRUNCATE “removes” rows. Actually, TRUNCATE does not remove data, but rather deallocates whole data pages and removes pointers to indexes. The data still exists until it is overwritten or the database is shrunk. This action does not require a lot of resources and is therefore very fast.
Why truncate is a DDL command?
TRUNCATE is a DDL command
How to fix a corrupted table in a MySQL database?
Restart your MySQL server. You typically notice a database or table is corrupt when your application accesses the table or database.