Difference between Read Committed Snapshot and Snapshot
Excerpt from an upcoming MSSQLTips article about concurrency and Fabric warehouses:
One key difference between Read Committed Snapshot isolation (RCSI) and Snapshot isolation (SI) is that SI ensures transaction-level read consistency, whereas RCSI offers it at the statement level. For example, imagine you have a query with two select statements. With RCSI, the second statement might read different data if another connection has already updated it. In contrast, with SI, you read the data from the start of the transaction.
Picture SQL Server taking a snapshot of the data when you start the transaction, hence the name Snapshot isolation.
Yes, I am rocking SSMS 21 Preview 6.
