SQL Server: Add Columns When In Production Environment

Are there any issues/problems related to adding new columns (not indexed) into a table when the database is already online. Assume that the database is quite busy开发者_如何学C on a constant basis and the table in question has over 1'000'000 records. Thanks.

Well, adding a column into your running system will definitely cause some interruptions and will gobble up system resources, so at best, your database will feel slow, at worst, people won't be able to query and get results.

You need to find a window of quiet time to do this - e.g. during the night or on a weekend or something.