Dbgateway are the program that manage the database connectivity.
DB_GATEWAY_THREAD_RANGE controls the number of Dbgateway threads opened to all databases defined in the repository from nqsserver.
It is set in nqsconfig.ini.
The lower number in the range is the number of threads that are kept open before Oracle BI Server takes action. If the number of open threads exceeds the low point in the range, Oracle BI Server terminates idle threads. For example, if DB_GATEWAY_THREAD_RANGE is set to 40-200 and 75 threads are open, Oracle BI Server terminates any idle threads.
When an error message contains the term “Dbgateway”, it suggests that the database connectivity is the source of the error.