11.6. Multi-Source Models: SELECT, UPDATE and DELETE

A multi-source query against a SELECT/UPDATE/DELETE may affect any subset of the sources based upon the evaluation of the WHERE clause.

The multi-source column may not be targeted in an update change set.

The sum of the update counts for UPDATEs/DELETEs will be returned as the resultant update count.

When running under a transaction in a mode that detects the need for a transaction and multiple updates may performed or a transactional read is required and multiple sources may be read from, a transaction will be started to enlist each source.