Difference between DELETE and TRUNCATE

DELETE is a DML(Data Manipulation Language) command and is used when we specify the row(tuple) that we want to remove or delete from the table or relation. The DELETE command can contain a WHERE clause. If the WHERE clause is used with the DELETE command then it removes or deletes only those rows(tuple) that satisfy the condition otherwise by default it removes all the tuples(rows) from the table.  Remember that DELETE logs the row deletions.

Syntax: DELETE command 

DELETE FROM TableName 
WHERE condition; 

TRUNCATE is a DDL(Data Definition Language) command and is used to delete all the rows or tuples from a table. Unlike the DELETE command, the TRUNCATE command does not contain a WHERE clause. In the TRUNCATE command, the transaction log for each deleted data page is not recorded. Unlike the DELETE command, the TRUNCATE command is fast. We cannot roll back the data after using the TRUNCATE command. 

Syntax: TRUNCATE command

TRUNCATE TABLE  TableName;

Let us see the difference between DELETE and TRUNCATE commands are as follows: 

Delete	Truncate
The DELETE command is used to delete specified rows(one or more).	While this command is used to delete all the rows from a table.
It is a DML(Data Manipulation Language) command.	While it is a DDL(Data Definition Language) command.
There may be a WHERE clause in the DELETE command in order to filter the records.	While there may not be WHERE clause in the TRUNCATE command.
In the DELETE command, a tuple is locked before removing it.	While in this command, the data page is locked before removing the table data.
The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row.	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.
DELETE command is slower than TRUNCATE command.	While the TRUNCATE command is faster than the DELETE command.
To use Delete you need DELETE permission on the table.	To use Truncate on a table we need at least ALTER permission on the table.
The identity of the fewer column retains the identity after using DELETE Statement on the table.	Identity the column is reset to its seed value if the table contains an identity column.
The delete can be used with indexed views.	Truncate cannot be used with indexed views.
This command can also active trigger.	This command does not active trigger.
DELETE statement occupies more transaction spaces than Truncate.	Truncate statement occupies less transaction spaces than DELETE.

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