Oracle on Itanium and HP-UX 11.31

From: Allan Nelson <>
Date: Wed, 16 Jul 2008 07:24:43 -0500
Message-ID: <>

We are on Oracle and HP-UX 11.11. We have a number of queries that wait on the CAS latch in Oracle. My understanding of this is that the CAS latch code path in Oracle on HP-UX makes up for a deficiency in the PA_RISC instruction set in that it does not support an atomic compare and swap instruction on the CPU.

We are getting ready to replace our database hardware with Itanium based servers from HP. I was hoping that the CAS latch issue would go away, along with the fact that HP cannot share latches for read access. But then one of the Hotsos guys told me he had talked to Steve Adams about a year ago and that the problem still persisted. Can anyone confirm this? Does HP-UX 11.31 on Itanium still require the simulation of the CAS instruction in the Oracle implementation for that platform?


Received on Wed Jul 16 2008 - 07:24:43 CDT

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