How to change ASM SYS Password and Creating SYSASM user 11g.

Things tried: SQL> select INSTANCE_NAME from v$instance; INSTANCE_NAME —————- +ASM SQL> ALTER USER sys IDENTIFIED BY <new_password> REPLACE <old_password>; ALTER USER sys IDENTIFIED BY <new_password> REPLACE <old_password> * ERROR at line 1: ORA-01109: database not open We can not change the password for ASM databases via alter user command.Because passwords are managed through password file […]

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Tuning indexes on RAC environments-4

Excessive undo block shipment and contention for undo buffers I have seen this scenario in one my projects where  Oracle EBS workload is high. When a select statement needs to read a block with active transactions, it has to cleanout the block and undo the changes to create a CR version. If the active transactions […]

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Tuning indexes on RAC environments-3

Reversing the index key This is accomplished by executing the following SQL statement: ALTER INDEX <index_name> REBUILD REVERSE; A reverse key index will invert the bytes of the index key column, so that values originally stored in the same block may be spread across multiple index leaf blocks. That will reduce buffer busy contention especially […]

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Tuning indexes on RAC environments-2

Globally busy buffers due to contention for index leaf and branch blocks As we discussed in previous sessions, because of batch INSERT high concurrency could occur for a relatively small set of index leaf and branch blocks, where index keys are populated with monotonically ascending values.The symptoms are increased frequencies and wait times for a […]

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Tuning indexes on RAC environments-1

Introduction and Significance of tuning indexes in RAC environments. Oracle E-Business environment with financial modules like AP and GL having large scale payment invoices transaction. Let me take example of one my public sector clients, they do process of 3 million payment instructions every night. Such most insert intensive applications running on RAC the frequency […]

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Index Performance Tuning Techniques for RAC

It’s been quite some time since my readers are requesting to see some posts on RAC performance tuning concepts and practices. In the process of testing some of the tuning techniques, as well as discussing and interpreting the results, I am preparing a four-day in depth session to understand index performance tuning techniques for RAC. […]

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Are you an Oracle DBA ?

Every DBA needs to know how to do their work under pressure, while facing crisis after crisis. Our most important contribution is to keep the database running. It’s an on-call function; you never know what might happen. Half the branch was up all night last night restoring a database because of a failure. Data recovery […]

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How to alter Oracle Cluster Registry (OCR) and Voting Disk

ADD/REMOVE/REPLACE OCR Device Note: You must be logged in as the root user, because root own the OCR files. Make sure there is a recent copy of the OCR file before making any changes: ocrconfig –showbackup If there is not a recent backup copy of the OCR file, an export can be taken for the […]

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GPFS use with Oracle

When utilizing GPFS with Oracle, configuration and tuning considerations include: When setting up your LUNS it is important to: Create the logical volumes such that they map one to one with a volume group and a volume group be one to one with a LUN which is a single RAID device. Not stripe logical volumes […]

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R12 RAC Cloning

RAC Cloning Details Note  : 559518.1 : Cloning Oracle Applications Release 12 with Rapid Clone on RAC Enabled Systems Patch : 5767290  : RAC-TO-RAC SUPPORT WITH RAPIDCLONE Supported Scenarios R12 Autoconfig Enabled on the dbTier and appsTier RAC conversion performed using on Note 388577.1. (This is the only RAC conversion method supported with Rapid Clone) […]

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RAC instance that use Veritas Clustered System

1) RAC RDBMS and infrastructure directories to be copied from the primary node 2) Setup SSH trusts between the nodes. 3) Export oracle home $ export ORACLE_HOME=/u01/app/oracle/product/9.2.0.4.rac 4) Relink the oracle binaries. $ relink all Check for errors if any. 5) Bring over following files/directories from primary node $ ORACLE_BASE/admin/<sid> $ ORACLE_HOME/network/admin/listener.ora $ ORACLE_HOME/network/admin/tnsnames.ora 6) […]

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