RSTs and concurrent loads
There is a known issue that occurs when users run concurrent loads into an RST and the loads contain rows with new (previously undefined) security masks. The concurrent loads could fail with the error Could not serialize - transaction aborted.
To avoid the load error, create a test table in the same database that contains the target table for the concurrent loads that failed. Insert a sample row into the test table for each security mask that is used in the failed load commands. This defines each security mask in the database, and you can reissue the load commands to load the data into the target RST.