When increasing the size of VARCHAR column on a large table could there be any problems?

sql-server sql-server-2008 varchar alter-column
Paul T Davies picture Paul T Davies · Sep 22, 2011 · Viewed 110.4k times · Source

I'm using SQL Server 2008 and I need to make a VARCHAR field bigger, from (200 to 1200) on a table with about 500k rows. What I need to know is if there are any issues I have not considered.

I will be using this TSQL statement:

ALTER TABLE MyTable
ALTER COLUMN [MyColumn] VARCHAR(1200)

I've already tried it on a copy of the data and this statement had no ill effects that I could see.

So are there any possible problems from doing this that I may not have considered?

By the way, the column is not indexed.

Answer

gbn picture gbn · Sep 22, 2011

This is a metadata change only: it is quick.

An observation: specify NULL or NOT NULL explicitly to avoid "accidents" if one of the SET ANSI_xx settings are different eg run in osql not SSMS for some reason

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