RE: is there any downtime required for adding new column for a large table..and adding a newe table

SSC Guru

Points: 186127

September 2, 2014 at 6:03 am

Hardy21 (9/2/2014)
Adding new table doesn't require downtime at all.
If your queries are not using SELECT * then you are ok to add new column (as it will not affect your application functionality). To check locks while adding new column, you should add column in your test server & see the result.
Adding column will lock the table.
A table, as a whole, has a single schema (set of columns, with associated types). So, at a minimum, a schema lock would be required to update the definition of the table.

The second paragraph of that is copied from here, and if you read through that thread, your answer isn't strictly correct.

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

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