Delete
|
Truncate
|
In
Delete Query we can use Where Clause
|
In
Truncate Query we can not use Where Clause
|
Syntax
DELETE
FROM
[Table_Name]
or
DELETE
FROM
[Table_Name] WHERE
[Condition]
|
Syntax:
TRUNCATE
TABLE
[Table_Name]
|
| Comparing the Delete is Slower than truncate | Comparing the Truncate is faster than the delete query |
| In Delete Query we can delete single only or multiple rows by using where clause. | In Truncate Query All the rows data truncated from table. |
| We can use triggers when delete query is executed . | We can not use triggers when truncate query is executed. |
| Delete query is logs the data. | Truncate can not log the data. |
| Delete query delete the data from table using row by row scenario. | Truncate query truncate the data from table using page by page scenario. |
| Delete can not reset the identity value in a table. | Truncate can reset the identity value in a table. |
It
does not claims the memory after delete operation is performed
Example:
Create
table
CREATE
TABLE
TempStudent
(
FName
varchar(100),
LName
varchar(100)
)
Insert
some dummy data
Insert
into
TempStudent(FName,LName)
VALUES('Rakesh','Kalluri')
Go
1000
Check
the memory used for this table.
exec
sp_spaceused
'TempStudent'
Delete
data from table
DELETE
FROM
TempStudent
Check
the memory used for this table after delete
exec
sp_spaceused
'TempStudent'
 |
It
claims the memory after truncate operation is performed
Example:
Create
table
CREATE
TABLE
TempStudent
(
FName
varchar(100),
LName
varchar(100)
)
Insert
some dummy data
Insert
into
TempStudent(FName,LName)
VALUES('Rakesh','Kalluri')
Go
1000
Check
the memory used for this table.
exec
sp_spaceused
'TempStudent'
Truncate
data from table
TRUNCATE
TABLE
TempStudent
Check
the memory used for this table after truncate
exec
sp_spaceused
'TempStudent'
 |
1 . ROW_NUMBER () OVER ( [PARTITION BY CLAUSE] < ORDER BY CLUASE >): Returns the sequantial number of a row within the a partition of result set at 1 for the first row of the each partition. 2. RANK () OVER ( [PARTITION BY CLAUSE] < ORDER BY CLUASE >): Returns rank for rows within the partition of result set. 3. DENSE_RANK () OVER ( [PARTITION BY CLAUSE] < ORDER BY CLUASE >): Returns rank for rows within the partition of result set.With out any gaps in the ranking. 4. NTILE ( INTEGER_EXPRESSION ) OVER ( [PARTITION BY CLAUSE] < ORDER BY CLUASE >): Distributes the rows in an ordered partition into a specified number of groups. Examples: --create Employee table create table Employee ( EmpId int identity ( 1 , 1 ) primary key , ...
Thank you so much
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