José Valerio Oracle Technology

Archive for the ‘Internals’ Category

Global Cache Waits – White Paper

07.02.2010 · Posted in 10g R1, 10g R2, Internals, RAC, White Papers

Who should read this white paper? This white paper is intended to be accessible to those who are not relatively new to the Real Applications Cluster performance. Familiarity with advanced Oracle concepts and SQL language is assumed. About Technical Reviewers Pablo Albeck – Oracle Practice Manager at Oracle Corporation, with several years of experience in ...

RAC LMS processes

05.25.2010 · Posted in Internals, Performance, RAC

Background Processes From 10g and over, Real Application Cluster databases has two new background processes: LMON – The Global Enqueue Service Monitor monitors the entire cluster to manage the global enqueues and the cluster resources. LMON manages instance and process failures and the associated recovery for the Global Cache Service (GCS) and Global Enqueue Service ...

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RAC Interconnect Performance

05.19.2010 · Posted in Internals, Performance, RAC

The contention in blocks can be measured by using the block transfer statistic. The first step is to determine block transfer time examining  the gv$sysstat view: global cache cr block receive time global cache cr blocks received. The time is determined by calculating the ratio of global cache cr block receive time to global cache ...

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Clusterware para proteger una base Oracle Single Instance

03.06.2010 · Posted in 10g R2, Internals, RAC

During 2007 I wrote a spanish white paper about the use of clusterware to protect single instances, this is not a well known use of clusterware, not translated to english. Step by Step – “Cluster Filesystem  Case” Abril 2007 Version 1.05 Step-by-Step: Utilizando el Clusterware de Oracle para proteger una base Oracle single instance “Entienda ...

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Oracle Internals – How to remaster an object in RAC

07.17.2009 · Posted in 10g R2, Internals, RAC

To understand re-mastering please read in my blog the previous post explaining differences between versions. 1. Log in as SYSDBA and find the segment object number SELECT data_object_id FROM dba_objects WHERE owner = ‘JVALERIO’AND object_name = ‘TESTDRM1′; data_object_id ————— 23098 data_object_id: Object number of the segment which contains the object. If you want to remaster at ...

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Oracle Internals – RAC Dynamic Re-mastering

07.17.2009 · Posted in 10g R1, 10g R2, Internals, RAC

Remastering is the ability to move the ownership of a resource between instances of Real Application Clusters. Dynamic resource remastering is used to implement resource affinity for increased performance. Resource affinity optimizes the system in situations where update transactions are being executed on one instance. When activity shifts to another instance the resource affinity will ...

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Oracle Internals – RAC Enqueues

06.26.2009 · Posted in Internals, RAC, RDBMS

The Enqueues are locks that serialize access to database resources. In general this indicates that the session is waiting for a lock that is held by another session. –******************************************************* – – H O L D E R S & W A I T E R S — http://jose-valerio.com.ar – – ******************************************************* SELECT inst_id, DECODE(request,0,’Holder: ‘,’Waiter: ...

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