In the new features of Oracle Database 12cR2 (12.2.0.1) DBCA can already be used to create dataguard on the standby side. Below is the environment detail: Type Hostname db_unique_name Primary host01 orclpri Standby host02 orclsby Enable force logging on primary. SQL> alter database force logging; Database altered. SQL> select name,force_logging from v$database; NAME FORCE_LOGGING ————————— […]
Monthly Archives: January 2018
Contention-Related Wait Events
Contention-Related Wait Events : It is common to see the gc cr block busy and gc current block busy wait events in Oracle RAC systems. These events occur when a consistent read or current block is needed from another instance yet it is taking some time to receive that block, and the sending of the […]
Oracle Internals – Fixed Objects – Part 1
Dynamic Performance Views Oracle contains a set of underlying views that are maintained by the database server and accessible to the database administrator user SYS. These views are called dynamic performance views because they are continuously updated while a database is open and in use, and their contents relate primarily to performance. Although these views […]
Load-oriented oracle rac wait events
Load-oriented oracle RAC wait events : The load-oriented wait events indicate that a delay in processing has occurred in the GCS, which is usually caused by high load, CPU saturation and would have to be solved by additional CPUs, load-balancing, off loading processing to different times or a new cluster node. For the events mentioned, […]
Message-Oriented Oracle RAC wait events
Message-Oriented Oracle RAC wait event The message-oriented wait event statistics indicate that no block was received because it was not cached in any instance. Instead, a global grant was given, enabling the requesting instance to read the block from disk or modify it. If the local instance is the resource master, the grant happens immediately.If […]
opatch version – Initial heap size set to a larger value than the maximum heap size
The below issue was faced by my fellow DBA while in checking OPatch version in Grid Home, Interestingly the same OPatch utility works fine in RDBMS Home Issue-OPatch version command failed with below error on GRID_HOME but it was working fine on DB home Error:- opatch version Error occurred during initialization of VM Initial heap […]
Grouping Oracle Rac Wait Events
To determine the amount of work and cost related to inter-instance messaging and contention, examine block transfer rates, remote requests made by each transaction, the number and time waited for global cache events as described under The response time for cache fusion transfers is determined by the messaging and processing times imposed by the physical […]
Block-Related Oracle Rac Wait Events – Part 2
An event can be anything that Oracle has to perform on behalf of a set of instructions sent by the user interface. The term “wait” is used because every time a user connects to your application, a resource is allocated to perform tasks on its behalf. The waiting comes when a session is waiting for […]
Accessing Oracle DBaaS Monitor
Database deployments of single-instance databases on Oracle Database Cloud Service include Oracle DBaaS Monitor, a built-in monitor that provides a wide spectrum of information about Oracle Database and operating system status and resource usage. You can access Oracle DBaaS Monitor in the following ways: Using the “Open DBaaS Monitor Console” menu item Using a direct […]
Difference Between Virtual Index and Invisible Index
Virtual Index Virtual indexes allow us to simulate the existence of an index and test its impact without actually building the actual index. Only sessions marked for Virtual Index usage will be affected by their existence. Their creation does not affect new sessions. Virtual indexes will be used only when the initialization parameter “_use_nosegment_indexes” is […]