Forum Discussion
Scheduled Refresh against data source updates
Hi y'all! I'm looking for a document that explains what happens with the following scenario: - power bi service, with a scheduled refresh every t1-time, connected to an azure data source - tha...
hi Anonymous, yes that's what I'm suggesting and I agree on that a number of things can happen. Just wondered if there was any doc.
Anyway, what do you mean with "dirty read from the source"? Still using Power BI?
dtrovato If your queries include "with(nolock)" they will perform dirty reads on the data. This means that the query will run and return data despite any locks being held on the table. The "dirty" means that if there is a process writing against the table as you query it, you may get the "old" data. In many cases this is ok, in others it wouldn't be. Depends largely on what you are reporting on.
- Just a note with the dirty reads is that they still place a schema lock on the table. So if there is a dirty read happening and for example an Index rebuild is trying to start, it cannot start until the dirty read completes.
