Repeatable Read and Serializable Isolation Levels (45 minutes)

Serializable and Repeatable Read isolation levels offer protections so your users won’t see weird or incorrect data — but there are tradeoffs for those protections.
In this course, you’ll dig into:
- How to tell if your existing applications are using these types of isolation levels
- When you might want to raise your isolation level in SQL Server
- The tradeoffs you make if you choose serializable or repeatable read with disk based tables.
Note: In this course, we focus on disk-based tables. In-Memory OLTP (“Hekaton”) works differently — it’s not lock-based! Learn about In-Memory OLTP and Isolation Levels here.
Course scripts
https://github.com/LitKnd/SQLWorkbooks/tree/main/repeatable_read_and_serializable_isolation_levels
Each video in this course has English captions available, as well as a transcript below the video.
Modules
Learn
Lessons
- Demo: Give me correct data or give me death (15 minutes)
- Animated diagram of the index intersection problem (6 minutes)
- How you can get serializable isolation, even if you didn’t ask for it (4 minutes)
- How to tell if apps are using repeatable read or serializable (5 minutes)
- What’s the best way to get correct data? (7 minutes)