OSB 11g Split-Join

Oracle Service Bus’s Split-Join feature lets you split a service payload, such as an order, into individual messages for concurrent processing. Concurrent processing, as opposed to sequential processing, greatly improves service performance. Split-Join achieves this task by splitting an input message payload into sub messages (split), routing them concurrently to their destinations, and aggregating the responses into one overall return message (join).
This process of payload splitting and response aggregation is called a Split-Join pattern.

Split-Joins are particularly useful for optimizing overall response times in scenarios where payloads delivered by faster systems are being directed to responding services on slower systems. Without Split-Join, individual messages in a payload are normally resolved in sequential order by the recipient, which can take a long time if the responding system is slow.

(The overall response time is the sum of the individual response times for each message.) With Split-Join, multiple messages are processed simultaneously, which reduces burden on the responding system and greatly enhances response times. (The overall response time is roughly that of the longest individual message’s response time plus some minor system overhead.)

For split join hands on refer the below blog post:
http://biemond.blogspot.com/2008/11/split-join-in-oracle-service-bus.html