Sessions and Instances
Because the Stream operator uses Teradata SQL sessions in its communication with Teradata Database, it does not use load slots. The Stream operator provides continuous updates using row level locking, allowing constant load operations in the background during normal system use.
Both a minimum and a maximum number of sessions can be used by the Stream operator. The minimum specification is one. The default is one session for each operator instance.
The number of sessions is evenly distributed among the number of operator instances. If 20 sessions are requested and four instances of the operator are invoked, then each instance will receive five of the sessions.
Other Session Limits
The values that you specify with the Stream operator MinSessions and MaxSessions attributes are not the only factors that limit the number of sessions that the Stream operator establishes with the Teradata Database. The other limiting factors are:
When the Stream operator executes, the actual session limit is determined by the first limiting factor that is encountered.