SQL Server/T-SQL/Table/TRUNCATE TABLE — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Текущая версия на 10:19, 26 мая 2010
Timing the delete and truncate statements
28>
29> create table employee(
30> ID int,
31> name nvarchar (10),
32> salary int,
33> start_date datetime,
34> city nvarchar (10),
35> region char (1))
36> GO
1>
2> insert into employee (ID, name, salary, start_date, city, region)
3> values (1, "Jason", 40420, "02/01/94", "New York", "W")
4> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (2, "Robert",14420, "01/02/95", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (4, "Linda", 40620, "11/04/97", "New York", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (5, "David", 80026, "10/05/98", "Vancouver","W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (6, "James", 70060, "09/06/99", "Toronto", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (7, "Alison",90620, "08/07/00", "New York", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W")
3> GO
(1 rows affected)
1>
2> select * from employee
3> GO
ID name salary start_date city region
----------- ---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W
2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N
3 Celia 24020 1996-12-03 00:00:00.000 Toronto W
4 Linda 40620 1997-11-04 00:00:00.000 New York N
5 David 80026 1998-10-05 00:00:00.000 Vancouver W
6 James 70060 1999-09-06 00:00:00.000 Toronto N
7 Alison 90620 2000-08-07 00:00:00.000 New York W
8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N
9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected)
1>
2>
3>
4> DECLARE @starttime DateTime
5> DECLARE @endtime DateTime
6> DECLARE @totaltime Int
7>
8> SET @starttime = GetDate()
9> DELETE FROM employee
10> SET @endtime = GetDate()
11>
12> SET @totaltime = DateDiff(ms, @starttime, @endtime)
13> PRINT "Time to Delete: " + CONVERT(VarChar(10), @totaltime)
14>
15> SET @starttime = GetDate()
16> TRUNCATE TABLE employee
17> SET @endtime = GetDate()
18>
19> SET @totaltime = DateDiff(ms, @starttime, @endtime)
20> PRINT "Time to Truncate: " + CONVERT(VarChar(10), @totaltime)
21>
22> drop table employee
23> GO
(9 rows affected)
(9 rows affected)
Time to Delete: 13
(9 rows affected)
Time to Truncate: 0
1>
2>
TRUNCATE a TABLE
28>
29> create table employee(
30> ID int,
31> name nvarchar (10),
32> salary int,
33> start_date datetime,
34> city nvarchar (10),
35> region char (1))
36> GO
1>
2> insert into employee (ID, name, salary, start_date, city, region)
3> values (1, "Jason", 40420, "02/01/94", "New York", "W")
4> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (2, "Robert",14420, "01/02/95", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (4, "Linda", 40620, "11/04/97", "New York", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (5, "David", 80026, "10/05/98", "Vancouver","W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (6, "James", 70060, "09/06/99", "Toronto", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (7, "Alison",90620, "08/07/00", "New York", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W")
3> GO
(1 rows affected)
1>
2> select * from employee
3> GO
ID name salary start_date city region
----------- ---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W
2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N
3 Celia 24020 1996-12-03 00:00:00.000 Toronto W
4 Linda 40620 1997-11-04 00:00:00.000 New York N
5 David 80026 1998-10-05 00:00:00.000 Vancouver W
6 James 70060 1999-09-06 00:00:00.000 Toronto N
7 Alison 90620 2000-08-07 00:00:00.000 New York W
8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N
9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected)
1>
2>
3>
4> DECLARE @starttime DateTime
5> DECLARE @endtime DateTime
6> DECLARE @totaltime Int
7>
8> SET @starttime = GetDate()
9> DELETE FROM employee
10> SET @endtime = GetDate()
11>
12> SET @totaltime = DateDiff(ms, @starttime, @endtime)
13> PRINT "Time to Delete: " + CONVERT(VarChar(10), @totaltime)
14>
15> SET @starttime = GetDate()
16> TRUNCATE TABLE employee
17> SET @endtime = GetDate()
18>
19> SET @totaltime = DateDiff(ms, @starttime, @endtime)
20> PRINT "Time to Truncate: " + CONVERT(VarChar(10), @totaltime)
21>
22> drop table employee
23> GO
(9 rows affected)
(9 rows affected)
Time to Delete: 13
(9 rows affected)
Time to Truncate: 0
1>
2>