Dehydration in Oracle SOA

Idempotence in BPEL :- 

Idempotent Activity	Non Idempotent Activity
Does not dehydrate	Dehydrates
Related to Transient Process	Related to Durable process
Assign, Invoke	Wait, Receive, Pick(onMessage, onAlarm), checkpoint(), Dehydrate
Can be retried	Not Retried

So when you specify the idempotent property as "false" in the partner link of a BPEL process ,

• It becomes non idempotent and cause the BPEL process for dehydration and so a commit occurs . 
• It ends the current transaction of a BPEL process and start a new one.

If BPEL recovers from dehydration store idempotent activities are retried again.

Properties	Transient Process	Durable Process
When Dehydrated	only once the execution is completed.	Non idempotent activities. After End of Process. Mid process breakpoints.
Exception / Crash occurs	No Trace in System.	this process instance appears in Oracle BPEL Control up to the last dehydration point (breakpoints activity) once the server restarts. If the server crashes before the process instance reaches the first mid process breakpoints activity, the instance is not visible in Oracle BPEL Control after the server restarts.
Example	Synchronous process. Any Process followed by setting in composite.xml  bpel.config.inMemoryOptimization = true bpel.config.completionPersistPolicy = off/deferred/faulted	Asynchronous process.

Reference : https://www.linkedin.com/today/author/sandeep-pachauri-b03a211b?trk=author-info__article-link