Adding Not Null with Default column to large Table

I am running an upgrade to an existing system which I have found is using the
Alter Table statement to add a Not Null with Default column to huge table
(100 million records). Not surprisingly it is taking rather a long time!
Can anyone give me any other options to perform this operation ?
I'm currently thinking about
1) Adding the column Nullable
2) Running multiple updates to the table
3) Altering the column to make it Not-Nullable.I don't think there's any way to get a performance boost, if that's what
you're after... Perhaps you could re-index the clustered index for the table
first with a large fillfactor. The ALTER may be going slowly because your
index pages are very full and adding the new column is forcing a lot of page
splits. But re-indexing the table may take just as long.
"Neil K" <Neil K@.discussions.microsoft.com> wrote in message
news:6037A939-4461-427E-8869-69B3171FA96F@.microsoft.com...
> I am running an upgrade to an existing system which I have found is using
the
> Alter Table statement to add a Not Null with Default column to huge table
> (100 million records). Not surprisingly it is taking rather a long time!
> Can anyone give me any other options to perform this operation ?
> I'm currently thinking about
> 1) Adding the column Nullable
> 2) Running multiple updates to the table
> 3) Altering the column to make it Not-Nullable.
>|||Not sure if you can set the constrainsts to nocheck, alter the column then
set the contraints to check
"Adam Machanic" <amachanic@.hotmail._removetoemail_.com> wrote in message
news:O2fPinbkEHA.1048@.tk2msftngp13.phx.gbl...
>I don't think there's any way to get a performance boost, if that's what
> you're after... Perhaps you could re-index the clustered index for the
> table
> first with a large fillfactor. The ALTER may be going slowly because your
> index pages are very full and adding the new column is forcing a lot of
> page
> splits. But re-indexing the table may take just as long.
>
> "Neil K" <Neil K@.discussions.microsoft.com> wrote in message
> news:6037A939-4461-427E-8869-69B3171FA96F@.microsoft.com...
>> I am running an upgrade to an existing system which I have found is using
> the
>> Alter Table statement to add a Not Null with Default column to huge table
>> (100 million records). Not surprisingly it is taking rather a long time!
>> Can anyone give me any other options to perform this operation ?
>> I'm currently thinking about
>> 1) Adding the column Nullable
>> 2) Running multiple updates to the table
>> 3) Altering the column to make it Not-Nullable.
>|||"Gene Black" <geblack@.hotmail.com> wrote in message
news:uN%23TUvdkEHA.1348@.TK2MSFTNGP15.phx.gbl...
> Not sure if you can set the constrainsts to nocheck, alter the column then
> set the contraints to check
Not a bad idea, but apparently constraints aren't checked when you do an
ALTER:
create table #a (id int)
insert #a values (2)
alter table #a with nocheck add constraint b check (id = 1)
alter table #a add b varchar(20) not null default('abc')|||Interesting suggestions ... thanks guys.
If I attempt my original plan of
1) Add column Nullable.
2) Run Batch updates for new column to Non-Null Value
3) Alter column to make non-null with default
Will the last step still take a long time to run , even though no data is
being added or amended, or will the Add Constraint Check be ignored ?|||"Neil K" <NeilK@.discussions.microsoft.com> wrote in message
news:3B4AF7FB-6138-4144-8B80-B014FCC18633@.microsoft.com...
> If I attempt my original plan of
> 1) Add column Nullable.
> 2) Run Batch updates for new column to Non-Null Value
> 3) Alter column to make non-null with default
> Will the last step still take a long time to run , even though no data is
> being added or amended, or will the Add Constraint Check be ignored ?
It should only take as long as a full table scan.
To simulate it, you could try:
SELECT COUNT(*)
FROM YourTable
WHERE SomeNonIndexedCol = SomeNonIndexedCol --Same column name
This will force a full table scan. You can add a NOLOCK hint or run it
with a READ UNCOMMITTED isolation level to make sure it doesn't interfere
with other processes.

adding new column

ALTER TABLE BFTITLE ADD COLUMN [RATETYPE] [NUMERIC] (10) NOT NULL ;
syntax is not working so can any one tell the right syntaxalter Table Bftitle Add [ratetype] [numeric] (10) Not Null|||Read BOL (SQL Server Books On Line) carefully. If a table already has rows in it, it isn't possible to add a NOT NULL column unless you also give the column a default value too (if you think about it, this only makes sense). I'm guessing on this, but I'd suggest trying:ALTER TABLE BFTITLE
ADD COLUMN [RATETYPE] [NUMERIC] (10) NOT NULL
DEFAULT 0-PatP|||ALTER TABLE BFTITLE
ADD COLUMN [RATETYPE] [NUMERIC] (10) NOT NULL
DEFAULT 0
-PatP

Close. This worked for me:

ALTER TABLE BFTITLE
ADD [RATETYPE] [NUMERIC] (10) NOT NULL
DEFAULT 0

I just removed "COLUMN" from your statement. Funny, I did not think it would be possible to add a non-nullable column, but you're right it can be done as long as you define a default value.

Following is proof:

create table foo (bar int)
go

insert foo (bar) values (1)
go
insert foo (bar) values (2)
go
insert foo (bar) values (3)
go
insert foo (bar) values (4)
go

ALTER TABLE foo
ADD [RATETYPE] [NUMERIC] (10) NOT NULL
DEFAULT 0

select * from foo

sp_columns foo

Adding Identity

how can i change a column attribute using alter table in sql server 2005. i want to add an identity property to my column userid , which deosn't have an identity property defined when created.

i tried this.

alter table userlookup alter column userid int identity(1,1) not null

i got this error:

Incorrect syntax near the keyword 'identity'.

As far as I know (I might be wrong), you can't do that if you already have some values in that column.

Anyway, if you particular table's requirements permit this (stuff like foreign keys pointing to it, etc.), you can just drop it and re-create it anew, this time as an identity column.

|||Open management studio
go to the table you need to alter
open the Modify context menu
edit changes
now right click and use the last menu item: Generate script for changes

You can use this way to know scripting template for any change you need.

In that case you will see that SSMS will create a temp table, performs a bulk insert, drops the original table and then renames the temp table to the original name.
something like this:

BEGIN TRANSACTION
SET QUOTED_IDENTIFIER ON
SET ARITHABORT ON
SET NUMERIC_ROUNDABORT OFF
SET CONCAT_NULL_YIELDS_NULL ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE dbo.Tmp_TRACE01
(
RowNumber int NOT NULL,
EventClass int NULL,
TextData ntext NULL,
NTUserName nvarchar(128) NULL,
ClientProcessID int NULL,
ApplicationName nvarchar(128) NULL,
LoginName nvarchar(128) NULL,
SPID int NULL,
Duration bigint NOT NULL IDENTITY (1, 1),
StartTime datetime NULL,
Reads bigint NULL,
Writes bigint NULL,
CPU int NULL
) ON [PRIMARY]
TEXTIMAGE_ON [PRIMARY]
GO
DECLARE @.v sql_variant
SET @.v = cast(N'760' as int)
EXECUTE sp_addextendedproperty N'Build', @.v, N'SCHEMA', N'dbo', N'TABLE', N'Tmp_TRACE01', NULL, NULL
SET @.v = cast(N'8' as int)
EXECUTE sp_addextendedproperty N'MajorVer', @.v, N'SCHEMA', N'dbo', N'TABLE', N'Tmp_TRACE01', NULL, NULL
SET @.v = cast(N'0' as int)
EXECUTE sp_addextendedproperty N'MinorVer', @.v, N'SCHEMA', N'dbo', N'TABLE', N'Tmp_TRACE01', NULL, NULL
GO
SET IDENTITY_INSERT dbo.Tmp_TRACE01 ON
GO
IF EXISTS(SELECT * FROM dbo.TRACE01)
EXEC('INSERT INTO dbo.Tmp_TRACE01 (RowNumber, EventClass, TextData, NTUserName, ClientProcessID, ApplicationName, LoginName, SPID, Duration, StartTime, Reads, Writes, CPU)
SELECT RowNumber, EventClass, TextData, NTUserName, ClientProcessID, ApplicationName, LoginName, SPID, Duration, StartTime, Reads, Writes, CPU FROM dbo.TRACE01 WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT dbo.Tmp_TRACE01 OFF
GO
DROP TABLE dbo.TRACE01
GO
EXECUTE sp_rename N'dbo.Tmp_TRACE01', N'TRACE01', 'OBJECT'
GO
ALTER TABLE dbo.TRACE01 ADD CONSTRAINT
PK__TRACE01__317735E1 PRIMARY KEY CLUSTERED
(
RowNumber
) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

GO
COMMIT