The only isolation level a Fabric warehouse uses; SET TRANSACTION ISOLATION LEVEL has no effect. Because locks are taken per table, two transactions changing one table can clash, and the later one fails and has to be rerun.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Snapshot isolation in context, with comparison tables and the common traps.
Terms in this definition
- Isolation level
Chosen with SET TRANSACTION ISOLATION LEVEL, this determines how much one transaction can see of, or be affected by, concurrent work. The levels range from READ UNCOMMITTED and READ COMMITTED through REPEATABLE READ to SNAPSHOT and SERIALIZABLE.
- Fabric Warehouse
A relational data warehouse in the classic style, offered as a Fabric item, that supports T-SQL fully, transactions included.
- Set
Secret permission in Key Vault for writing secrets; some older material refers to it as Create.
- Event
Table in Log Analytics where entries from Windows event logs are kept.
Related terms
- ACID
Four promises a database transaction makes: atomicity, consistency, isolation and durability. Azure Cosmos DB honours them, with snapshot isolation, only inside one logical partition, using stored procedures, triggers or transactional batch.
- Explicit transaction
A set of T-SQL statements wrapped between
BEGIN TRANand eitherCOMMITorROLLBACK, so that edits across multiple tables either all appear at once or are all discarded. In Fabric Warehouse these use snapshot isolation, and savepoints as well as named, marked and distributed transactions are unsupported.