Tag: oratidbit

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in December 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 #db12cR2 Credentials created using the DBMS_CREDENTIAL.CREATE_CREDENTIAL procedure are database objects that hold a username/password pair for authenticating and impersonating EXTPROC callout functions, remote jobs, external jobs and file watchers from the SCHEDULER.

#oratidbit #orcldb Oracle Advanced Queuing stores user messages in abstract storage units called queues. When business applications communicate with each other, producer applications enqueue messages and consumer applications dequeue messages.

#oratidbit #orcldb XStream consists of Oracle Database components and application programming interfaces (APIs) that enable client applications to receive data changes from an Oracle database and send data changes to an Oracle database.

#oratidbit #db12cR2 Init parameter ASM_IO_PROCESSES in 12.2 specifies the number of I/O worker processes to be started in an Oracle Automatic Storage Management (Oracle ASM) IOServer instance.

#oratidbit #db12cR2 Init parameter ENABLE_AUTOMATIC_MAINTENANCE_PDB in 12.2 can be used to enable or disable the running of automated maintenance tasks for all the PDBs in a CDB or for individual PDBs in a CDB.

#oratidbit #db12cR2 In 12.2 Oracle Multitenant license allows 252 PDBs in Enterprise Edition and 4096 PDBs in EE on Exadata.

#oratidbit #db12cR2 When the character set of the CDB root is AL32UTF8, any container in the CDB canSharding is a data tier architecture in which data is horizontally partitioned across independent databases. use a character set that is different from the CDB root and different from other containers in the CDB.

#oratidbit A proxy PDB provides access to another PDB in a remote CDB. Use the CREATE PLUGGABLE DATABASE statement to create a proxy PDB by referencing the other PDB. Use a proxy PDB when you want a local context for a remote PDB.

#oratidbit #db12cR2 Use FLASHBACK PLUGGABLE DATABASE command to rewind a PDB to any SCN without affecting other PDBs in a CDB. You can also create a restore point specific for a PDB, and rewind the PDB to this restore point without affecting other PDBs.

#oratidbit #orcldb database acquires a full table lock on the child table when no index exists on the foreign key column of the child table, and a session modifies a primary key in the parent table.

#oratidbit #Sharding is a data tier architecture in which data is horizontally partitioned across independent databases. Sharding provides linear scalability and complete fault isolation for the most demanding OLTP applications.

#oratidbit In Oracle Database 12c Release 1 (12.2.0.1) all shards and shard catalog must be non-CDB databases.

#oratidbit #db12cR2 Use the new -R option for the parallel upgrade utility (catctl.pl) to resume the upgrade at the point of failure, so that only the missing upgrade phases are rerun – Automatic Resume After Failed Upgrades feature.

#oratidbit #db12cR2 Use the new -T option for the parallel upgrade utility (catctl.pl) to set user tablespaces automatically to READ-ONLY during an upgrade. After the upgrade, the tablespaces are changed back automatically to READ/WRITE.

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in November 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 The ALTER DATABASE LINK statement is intended only to update fixed-user database links with the current passwords of connection and authentication users.

#oratidbit #orcldb Oracle database issues implicit COMMIT 1) before any syntactically valid DDL statement 2) after any DDL statement that completes without an error.

#oratidbit #orcldb Database virtual columns supported only in relational heap tables. Virtual columns are not supported for index-organized, external, object, cluster, or temporary tables.

#oratidbit When flashback is enabled or when there are guaranteed restore points, the background process RVWR writes flashback data to flashback database logs in the fast recovery area.

#oratidbit If neither AS SYSBACKUP nor AS SYSDBA is specified in the RMAN connection string, then the default used is AS SYSDBA.

#oratidbit You cannot use Flashback Database to undo a shrink data file operation. You may take the shrunken file offline, flash back the rest of the database, and then later restore and recover the shrunken data file.

#oratidbit During block media recovery, the affected data file is online and usable. Only the blocks actually being recovered are unavailable during the recovery.

#oratidbit The V$FLASHBACK_DATABASE_STAT view shows the bytes of flashback data logged by the database. The FLASHBACK_DATA and REDO_DATA columns describe bytes of flashback data and redo data written respectively during the time interval.

#oratidbit #orcldb The FLASHBACK TABLE is executed in a single transaction, regardless of the number of tables specified in the Flashback list. If the operation fails on any table, then the entire statement fails.

#oratidbit #orcldb To FLASHBACK DATABASE the database must run in ARCHIVELOG mode.

#oratidbit #orcldb When using DROP PLUGGABLE DATABASE statement to drop a PDB, you must be connected to the ROOT PDB as SYSDBA or SYSOPER.

#oratidbit #db12cR2 Use the new -T option for the parallel upgrade utility (catctl.pl) to set user tablespaces automatically to READ-ONLY during an upgrade. After the upgrade, the tablespaces are changed back automatically to READ/WRITE.

#oratidbit #db12cR2 Use the new -R option for the parallel upgrade utility (catctl.pl) to resume the upgrade at the point of failure, so that only the missing upgrade phases are rerun – Automatic Resume After Failed Upgrades feature.

#oratidbit #db12cR2 The Parallel Upgrade Utility (catctl.pl) parameter -N controls the number of parallel SQL processes to use when upgrading databases.

#oratidbit #oracleoem All operations performed by Enterprise Manager users such as creating users, granting privileges, starting a remote job, can be recorded and audited. Enable the Audit Framework using “emcli enable_audit”.

#oratidbit #oracleoem My Oracle Support connectivity in OEM Cloud Control enables you to view service request information, obtain patch recommendations, and download plug-ins and other entities to the Software Library, all from the Cloud Control Console.

#oratidbit #oracleoem Always-On Monitoring is a self-contained application that is supplied with the Enterprise Manager software distribution (sysman/ems directory) and is also available via the Self-Update function in Enterprise Manager.

#oratidbit Oracle Linux provides the yum utility to install or upgrade RPM packages. Yum also installs or upgrades any package dependencies.

#oratidbit #db12cr2 Oracle Diagnostic Pack (AWR/ADDM) can be used on an Oracle Active Data Guard standby database that is open read-only.

#oratidbit 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.

#oratidbit #db12cR2 Init parameter PDB_OS_CREDENTIAL can be used to ensure that operating system interactions are performed as a less powerful user and provide the ability to protect data belonging to one PDB from being accessed by users connected to another PDB.