Add IDENTITY to an existing column with an empty matching table, ALTER TABLE SWITCH, a reseed, and full dependency checks.
Adding a NOT NULL Column With a Default to a Big Table
Add a NOT NULL column with a default safely, distinguish metadata changes from row updates, and plan a staged Standard edition rollout.
Rename a Column or Table in SQL Server Safely
To rename a column in SQL Server, call sp_rename with the table and column name, the new name and the word COLUMN. This post tests the rename on a demo database and shows what it leaves behind: a broken view, an old constraint name and permissions that stay. It ends with a safe way to swap two column names.
CHECK Constraints and NULL: Why Unknown Passes the Test
Why does a CHECK (Quantity > 0) happily store a row with no quantity? Three-valued logic, a small demo, and the NOT NULL fix.
Updatable Views: When INSERT and UPDATE Work Through a View
A view is only a doorway to the table behind it. I show which writes get through, which get rejected, and why CHECK OPTION earns its place.
ALTER TABLE REBUILD: Fixing a Heap Without a Clustered Index
A heap with widening rows collects forwarded records. Here is how to measure them, fix them and know when the fix will not last.
Explicit Identity Values: Loading Rows With Their Old Keys
Moving rows and keeping their old keys? Here is the safe order of steps, and the counter check that saves you from a collision.