Re: Wait Event - enq: IV - contention

From: Jonathan Lewis <>
Date: Tue, 27 Mar 2018 17:51:54 +0000
Message-ID: <LO1P123MB0977058D4112C288B362FEB5A5AC0_at_LO1P123MB0977.GBRP123.PROD.OUTLOOK.COM>

If you convert decimal to Hexadecimal to ASCII:

P1 is just a repeat of the lock information, reading IV, mode 5 P2 is supposed to be an object_id for the IV lock, but yours actually reads "SYNC" P3 = 3

Which node is the process running on ? The IV is supposed to synchronising library cache invalidation across instances. Perhaps P3 = 3 is a large-scale function, perhaps it's saying that this instance is waiting for instance 3 (which might be 4 depending on whether Oracle is counting from 0 or 1 in this case).

One guess: do you see SGA resizes at the time this is happening - perhaps one instance starts resizing and locks up the other instances as it does so.

Jonathan Lewis

From: <> on behalf of Biju Thomas <> Sent: 27 March 2018 18:40
Subject: Wait Event - enq: IV - contention

Trying to troubleshoot a stuck program. The program gets stuck at a particular wait event 1 out of every 8 runs on an average. When the program completes, it finishes in few minutes. When it is stuck, the P1, P2 values are always the same. Can you please tell what the P1, P2, P3 values represent.

Current Wait Event              enq: IV - contention
Current Wait Class               Other
P1                         type|mode 1230372869
P2                         id1 1398361667
P3                         id2 3
Object                   None

They are not OBJECT_IDs.

Version: Oracle database
RAC Database, 4 nodes.

Thanks for your help.
Biju Thomas


Biju Thomas<>
-- Received on Tue Mar 27 2018 - 19:51:54 CEST

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