Reducing column size

I want to reduce the length of a column in one of my database tables
from varchar(2048) to varchar(900), basically so I can create an index
on the column to gain much improved performance.
To do this, I am executing the following statement:
ALTER TABLE myTable ALTER COLUMN description VARCHAR(900) NULL
Executing this in query analyzer results in the following error:
Server: Msg 8152, Level 16, State 9, Line 1
String or binary data would be truncated.
The statement has been terminated.
If I make this change via Enterprise Manager, it appears as a warning
and I can click OK to ignore and make the change. However, in query
analyzer this is treated as an error and the statement is not
performed.
What i want is to basically ignore this error and make the change
regardless. Is this possible?It basically tell you the data length in that column is more then varchar(900).
You can reduce the length of a column of the length less the length of the
data in that column.
review the data in that column which more the 900 char
Cheers
"jasonatkins2001@.hotmail.com" wrote:
> I want to reduce the length of a column in one of my database tables
> from varchar(2048) to varchar(900), basically so I can create an index
> on the column to gain much improved performance.
> To do this, I am executing the following statement:
> ALTER TABLE myTable ALTER COLUMN description VARCHAR(900) NULL
> Executing this in query analyzer results in the following error:
> Server: Msg 8152, Level 16, State 9, Line 1
> String or binary data would be truncated.
> The statement has been terminated.
> If I make this change via Enterprise Manager, it appears as a warning
> and I can click OK to ignore and make the change. However, in query
> analyzer this is treated as an error and the statement is not
> performed.
> What i want is to basically ignore this error and make the change
> regardless. Is this possible?
>|||Notice that you have data that is longer then 900 bytes and by forcing
the modification you will lose data.
The reason that the EM does it and the alter statement in the QA
doesn't work is that the EM doesn't really runs alter table statement.
Instead the EM creates a new table and then runs insert select from the
source table to the new table. Then it drops the old table, renames
the new table, and creates the table constraints and the references
from other tables to the new table.
Also notice that even if you'll have an index on a column that has 900
bytes, the index won't be very effective.
Adi
jasonatkins2001@.hotmail.com wrote:
> I want to reduce the length of a column in one of my database tables
> from varchar(2048) to varchar(900), basically so I can create an index
> on the column to gain much improved performance.
> To do this, I am executing the following statement:
> ALTER TABLE myTable ALTER COLUMN description VARCHAR(900) NULL
> Executing this in query analyzer results in the following error:
> Server: Msg 8152, Level 16, State 9, Line 1
> String or binary data would be truncated.
> The statement has been terminated.
> If I make this change via Enterprise Manager, it appears as a warning
> and I can click OK to ignore and make the change. However, in query
> analyzer this is treated as an error and the statement is not
> performed.
> What i want is to basically ignore this error and make the change
> regardless. Is this possible?