enq: PS - contention
Short Description
Enqueue wait. Parallel slave synchronisation.
Additional Information
An enqueue is a wait for a resource held by another. There is little documentation around this wait, but is parallel queries, the query coordinator (QC) uses a number of slaves to perform the query. This is seen when the query QC is attempting to allocate slaves for it’s use.
How to reduce this wait
Ensure the parallel query configuration has enough resources allocated without overloading the server.
Additional Links
Oracle Docs - VLDB and Partitioning Guide - Using Parallel Execution
Search online
If this article doesn't have the information you need you can try searching online. Remember, you can contribute suggestions to this page.