Oracle Tidbits – May 2017 #oratidbit

Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter and Google+ during weekdays in May 2017. You will also see these tidbits, one tidbit at a time, for each page refresh on the right side of this blog as well… Hope you find these helpful to learn something new or to remind you of its existence and use.

#oratidbit #orcldb #db12cR2 Starting with Oracle Grid Infrastructure 12c Release 2 (12.2), Oracle GI software is available as an image file for download and installation. Extract the image software into the directory where you want your Grid home to be located, and then run the gridSetup.sh script to start Oracle GI installation.
#oratidbit #orcldb #db12cR2 Starting with 12.2 RAC, SYSRAC administrative privilege is the default mode for connecting to the database by the clusterware agent on behalf of the Oracle RAC utilities such as srvctl.
#oratidbit #orcldb #db12cR2 In 12.2 manually upgrade the database using dbupgrade shell script instead of the catctl.pl perl script. dbupgrade starts up catctl.pl.
#oratidbit #orcldb #db12cr2 Optimizer Statistics Advisor analyzes how optimizer statistics are gathered, and then makes recommendations.
#oratidbit #orcldb #db12cr2 Use OCLUMON to query the Cluster Health Monitor repository to display node-specific metrics for a specified time period.
#oratidbit #orcldb #db12cr2 Each Oracle Cluster Health Advisor daemon (ochad) monitors the operating system on the cluster node and optionally, each Oracle Real Application Clusters (Oracle RAC) database instance on the node.
#oratidbit #orcldb #db12cr2 Oracle Clusterware uses policy-based management of servers and resources used by Oracle databases or applications.
#oratidbit #orcldb #db12cr2 Rapid Home Provisioning is a method of deploying software homes to any number of nodes in a data center from a single cluster, and also facilitates scaling, patching, and upgrading software.
#oratidbit #orcldb To administer Oracle multitenant container database, you must have the CDB_DBA role.
#oratidbit #orcldb DBCA can be used to create standby databases for non-multitenant primary databases using command qualifier createDuplicateDB. https://docs.oracle.com/database/122/SBYDB/creating-oracle-data-guard-physical-standby.htm#SBYDB-GUID-7C55FE8A-50C3-4601-9ADA-98BE6D65F1DD
#oratidbit #orcldb In an Oracle Database multitenant environment, the redo must be shipped to the root container of the standby database.
#oratidbit #orcldb An Oracle Data Guard far sync instance is a remote Oracle Data Guard destination that accepts redo from the primary database and then ships that redo to other members of the Oracle Data Guard configuration. Data files do not exist at the far sync instance.
#oratidbit #orcldb As of Oracle Database 12c Release 2 (12.2.0.1), when a physical standby database is converted into a primary you have the option to keep any sessions connected to the physical standby connected, during the switchover/failover operation if STANDBY_DB_PRESERVE_STATES initialization parameter is set.
#oratidbit #orcldb As the main function of a database upgrade is to create a new data dictionary, the upgrade can be tested for most of the upgrade functionality by using a copy of the database’s SYSTEM/SYSAUX tablespaces and ROLLBACK SEGMENT tablespace and marking all other tablespaces OFFLINE. This allows realistic timings to be obtained without having to copy an entire database.
#oratidbit #orcldb Make all tablespaces OFFLINE NORMAL or make READ ONLY except for SYSTEM, SYSAUX and those containing rollback segments prior to upgrade. This way if upgrade fails, only the SYSTEM and rollback datafiles need to be restored rather than the entire database.
#oratidbit #orcldb In 12c, the RMAN duplicate command has new “NOOPEN” option which clones the database but does not open the auxiliary. This feature can be used to duplicate a database to higher version.
#oratidbit #orcldb To compare the status of database before and after an upgrade, use the script dbupgdiag.sql available in MOS# 556610.1.
#oratidbit #orcldb Adaptive query optimization enables the optimizer to make run-time adjustments to execution plans and discover additional information that can lead to better statistics. http://docs.oracle.com/database/121/TGSQL/tgsql_optcncpt.htm#TGSQL221
#oratidbit #db12cR2 OEM Database Express Single Port Access for Multitenant Databases is enabled by executing “dbms_xdb_config.SetGlobalPortEnabled(TRUE)”. In the Login page, you can specify the PDB to which you want to connect. If it’s not specified, EM Express connects to the root container.
#oratidbit #orclebs To support online patching, Oracle E-Business Suite Release 12.2 uses a database service. On code levels lower than AD-TXK Delta 9, the service name is always ‘ebs_patch’. From the AD-TXK Delta 9 code level, the service name is defined by the value of the context variable ‘s_patch_service_name’.

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