One Friday afternoon, a junior developer was tasked with a seemingly simple change: add a new NOT NULL column to a fact table called FactTransactions . Following standard practice, she opened the SSDT project, added the column to the table definition, and hit “Publish.” SSDT helpfully generated the deployment script, showing a standard ALTER TABLE ADD command. She deployed to the development environment—no issues. Then to QA—fine.
A few years ago, a mid-sized financial analytics firm had a critical reporting database. Every night, a complex ETL process ran, and every morning, executives got their dashboards. The team used SSDT for version control and deployments—modeling the entire database schema as a Visual Studio project. sql server data tools
The fix? They learned that for large tables with a NOT NULL column and a default, SSDT’s “smart” offline deployment strategy (which avoids online ALTER operations that could lock the table for hours) backfires. They had to change the deployment settings: disable the “allow offline deployments” or explicitly tell SSDT to use an online ALTER TABLE ADD WITH VALUES command. One Friday afternoon, a junior developer was tasked
It’s a classic SSDT moment: brilliant for source control and repeatable builds, but occasionally too clever for its own good. Then to QA—fine