The question that I currently have: Is it possible to upgrade schemas [ Add tables/fields/indexes…] in SQLAzure while the database is in use and what are the
risks in doing this?
Some of our datatables have quite a lot of records (100million and up)
I think SQL Azure and SQL Server should have the same behavior. For SQL Server, when modifying a table use the ALTER TABLE statement, a schema modify lock is acquired on the table to block other connections.
For more information, please see the following document (the Locks and ALTER TABLE section):
ALTER TABLE (Transact-SQL)http://msdn.microsoft.com/en-us/library/ms190273.aspx