https://docs.microsoft.com/en-us/dotnet/api/system.data.isolationlevel

A database way to tell how isolated a task is from other tasks for the database.

In MDriven you set in SqlDatabaseConfig one isolation level for update UpdateIsolationLevel and one for read FetchIsolationLevel.

If you have a too low UpdateIsolationLevel extraction of new id's and timestamps my not be unique and cause problems with your data integrity