Configuration

This section explains each of the properties in the configuration blade.

General

Property	Description
Collection	This associates this Agent to a specific Collection and defaults to that of the current Data Stream.

Refer to Collections and Stream Hosts to understand more about Collections.

Behaviour

Property	Description
Behaviour	The input data will be evaluated in batches (Context) or row by row (Streaming). Context: The most recent set of context events are kept in memory and each streaming event is evaluated for a match. This is useful when one leg of (contextual) data changes slowly. Streaming: Events received from both legs are buffered for a specified time into a streaming window. The events in this window are evaluated for a match. This is useful for data that is received continuously from both legs.
Context Endpoint	The input endpoint that provides context: Left or Right. Events from this endpoint will not trigger batched matching. Applies to Context behaviour only.

Prefix

Property	Description
Left Prefix	The text prefixed on left endpoint attributes (default L).
Right Prefix	The text prefixed on right endpoint attributes (default R).
Only apply for duplicates	Tick to prefix only attributes identically named in both endpoints. Unticked by default, i.e. all attributes are prefixed.

It is recommended that this feature is used on new Join Agents rather than existing as downstream Agents will be affected by a change to the attribute names.

Select

Property	Description
Select List	The columns or attributes from both input payloads are listed - select those to be included in the output payload.

Join

Property	Description
Type	Inner Join: For each event, the engine waits for a match (as per the specified window) from the other leg of the Join. If a match is found, the resulting payload is pushed forward, otherwise the event is discarded. Outer Join: The resulting payload is pushed down the stream regardless of finding a match (as per the specified window), and the resulting payload substitutes null values for the other leg of the Join. Left Outer Join: Events from the right leg are discarded if no match is found (as per the specified window). Events from the left leg are pushed downstream regardless of finding a match, and the resulting payload substitutes null values for the right leg of the Join. Right Outer Join: Events from the left leg are discarded if no match is found (as per the specified window). Events from the right leg are pushed downstream regardless of finding a match, and the resulting payload substitutes null values for the left leg of the Join.
At most one match per record	Tick if at most one match per record should be returned - duplicated events will be discarded after the results have been combined. This applies to streaming events only - context data can be matched for every streaming event received. Eg. with context behaviour, an event for asset A is received. It's state attribute is a match to more than one context event. The first context match will be returned and the rest ignored.
On	One or more join criteria - each is made up of a left leg attribute, operator (=, >=, <=, >, <, !=) and right leg attribute.
Date-Diff Unit	Hour, Minute or Second (applies to Streaming behaviour only).
Date-Diff Max	The number of date-diff units used for the streaming window e.g. 15 minutes (applies to Streaming behaviour only).

Before configuring the Transformation, please ensure that its input endpoint is connected to a parent Agent which will be sending data to it.

Endpoints

Name	Description
Left	One of two payloads (or legs) to be combined.
Right	The second of two payloads (or legs) to be combined.
Output	The Agent publishes the resulting payload events to this endpoint and the attributes match the select list configuration property.
Error	If errors are encountered during the execution of this Agent they will be published on this endpoint.