Streams Queue Spilling

The Streams capture process enqueues the LCRs to the buffered queue in the Streams pool memory. By default, the LCRs are expected to be consumed, or dequeued, within 300 seconds. Unfortunately, this time duration is not configurable. If the LCRs are not dequeued within this time, then they are written to the disk queue spill table. This is called queue spilling.

Queue spilling can also happen if there is shortage of memory space in the Streams pool. Such shortage can result when a large number of LCRs are waiting acknowledgment from the apply process. These LCRs cannot be purged until after the acknowledgement is received.