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enq: HW - contention

Short Description

Enqueue wait. Segment High Water mark contention during concurrent inserts

Additional Information​

An enqueue is a wait for a resource held by another.

The enq: HW - contention is seen when a multiple sessions attempt to move the segment High Water Mark concurrently. This can be multiple independent sessions or a parallel insert.

How to reduce this wait​

Consider increasing freelists or moving segments to ASSM.

Consider adjusting the parallelism of the insert.

Oracle docs - Oracle Enqueue Names

Vineet Arya - enq: HW - contention- High Water Mark Brokered

Burleson - enq: HW contention tips

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