Enabling Oracle NUMA support in the Oracle DB 11GR2 release
Reference text:
Enable Oracle NUMA Support with Oracle Server Version 11gR2 (document ID 864633.1)
Suitable for:
Oracle database-enterprise edition-version 11.2.0.1 and later
Oracle Database-standard edition-version 11.2.0.1 and later
Information in this document applies to any platform.
Oracle on NUMA capable hardware
Checked for relevance on 11-mar-2013***
Details:
Oracle Numa (Non Uniform Memory Architecture) support can is used with large SMP multiprocessor environments with NUMA HARDW Is.
Enabling Oracle NUMA support effectively uses the underlying NUMA hardware and may improve DB performance.
Oracle NUMA support requires the right combination of hardware, OS, and Oracle DB version.
Starting with Oracle DB 11.2.0.1, the default Oracle NUMA support is disabled.
This document describes how Oracle NUMA support is enabled in the case of Oracle DB 11GR2
In environments prior to Oracle DB 11.2, using NUMA recommendations and NUMA support, see MOS article: note:759565.1
Be careful to enable NUMA support. Contact your hardware vendor to obtain information about NUMA compatibility for your hardware and operating system.
Recommended:
Customers who has tuned their Database specifically for NUMA can continue to run with NUMA enabled with Oracle Server Ver Sion 11.2.0.1.
It is strongly recommended to customers who want to enable NUMA does sufficient testing before going into production.
Let's go:
Steps to enable NUMA in Oracle DB 11.2:
When using Oracle DB 11.2 in a NUMA-compliant environment, the default Oracle will not detect NUMA compatibility for hardware and OS, and will not enable Oracle NUMA support
Set the following implicit parameter to enable NUMA support
_enable_numa_support=true
In addition, no other steps are required.
_enable_numa_support This parameter replaces the _enable_numa_optimization parameter. If you use the _enable_numa_optimization parameter instead of the _enable_numa_support parameter, there will be an alarm in alert log:
... _enable_numa_optimization is deprecated you use _enable_numa_support instead ....
Once the _enable_numa_support parameter is set in the parameter file and the Oracle DB 11.2 is running in a NUMA-compliant environment, the alert log for the DB instance will have feedback that NUMA support has enabled. And can show what NUMA configuration is detected.
For example, on a 8 NUMA domains Linux system with cores:
... NUMA system found and support enabled (8 domains-6,6,6,6,6,6,6,6) ...
Warning:
Disabling or enabling changes the performance of the application
Recommended for evaluation in a test environment before enabling NUMA support in a production environment
When Oracle NUMA support is disabled, the operating system and hardware configuration may need to be adjusted or reconfigured, please consult your hardware vendor for more information and recommendations.
