Tag: #db18c

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Oracle Tidbits – April 2018 #oratidbit

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in April 2018. Hope you find these helpful to learn something new or to remind you of its existence and use.

#oratidbit #db18c #Dataguard Broker 18c VALIDATE DATABASE SPFILE performs a comparison of server parameter file (SPFILE) entries between the primary database and a specified standby database.
#oratidbit #db18c #Dataguard A standby database can be refreshed over the network using one RMAN command, RECOVER STANDBY DATABASE.
#oratidbit #db18c If you have an existing Oracle Database with services that you want to migrate to 18c, you must install the new release Oracle Database software in the Oracle home, and then use DBUA to migrate those services.
#oratidbit #db18c Oracle Streams does not support any Oracle Database features added in Oracle Database 12c Release 1 (12.1) or later releases.
#oratidbit #orachk To run Oracle Grid Infrastructure checks in an environment with no Oracle Database has been installed, use the option -nordbms with orachk and exachk.
#oratidbit #db18c Before upgrading to Oracle Database 18c, you must set the COMPATIBLE initialization parameter to at least 11.2.0, which is the minimum setting for Oracle Database 18c.
#oratidbit To upgrade #orcldb 11g release 2 (11.2) Express Edition (Oracle Database XE) to 12c release 2 (12.2), you must first upgrade from XE to 12c release 1 (12.1.0.2) Enterprise Edition, and then upgrade to 12c release 2 (12.2).
#oratidbit #db18c Read-only Oracle Home: ORACLE_BASE_HOME is a subdirectory within the ORACLE_BASE directory that contains user-specific files, instance-specific files, and log files.
#oratidbit #db18c Read-only Oracle Home: ORACLE_BASE_CONFIG is same as the ORACLE_BASE directory that contains instance-specific dynamic files, such as configuration files.
#oratidbit Starting up the database in UPGRADE mode enables to open a database based on an earlier release. It also restricts log-ins to AS SYSDBA sessions, disables system triggers, and performs additional operations that prepare the environment for the upgrade.
#oratidbit #db18c New Parameter: ADG_ACCOUNT_INFO_TRACKING – Value of GLOBAL maintainins a single global copy of users account information across all Data Guard databases (primary and standby). Login anywhere will be denied when the login failure count is reached.
#oratidbit #db18c New Parameter: PARALLEL_MIN_DEGREE controls the minimum degree of parallelism computed by automatic degree of parallelism.
#oratidbit #db18c New Parameter: PRIVATE_TEMP_TABLE_PREFIX specifies the prefix that the database uses for private temporary tables. The default value used for the PRIVATE_TEMP_TABLE_PREFIX parameter is ORA$PTT_.
#oratidbit SQL*Plus command-line option –F[ast] changes the setting values as ARRAYSIZE = 100, LOBPREFETCH = 16384, PAGESIZE = 50000, ROWPREFETCH = 2, STATEMENTCACHE = 20.
#oratidbit SQL*Plus SET FEEDBACK command has an ONLY option to display the number of rows selected. No data is displayed.
#oratidbit #orcldb Initialization parameter INSTANCE_MODE indicates whether the instance is read-write, read-only, or read-mostly. A READ-MOSTLY instance is an Oracle instance that performs very few database writes.
#oratidbit #orcldb Initialization parameter ENABLE_AUTOMATIC_MAINTENANCE_PDB 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 #orcldb Initialization parameter CURSOR_INVALIDATION controls whether deferred cursor invalidation or immediate cursor invalidation is used for DDL statements by default. Prior to 12.2.0.1, immediate cursor invalidation was used.
#oratidbit #orcldb Init LONG_MODULE_ACTION enables the use of longer lengths for modules and actions. Module length was 48 bytes and action length was 32 bytes in releases prior to 12.2.0.1. If set to TRUE (the default value), then the length of both will be 64 bytes each.
#oratidbit #orcldb Initialization parameter MAX_IDLE_TIME specifies the maximum number of minutes that a session can be idle. After that point, the session is automatically terminated.
#oratidbit #db18c A CDB fleet provides the database infrastructure for scalability and centralized management of many CDBs. A CDB fleet is a collection of CDBs and hosted PDBs that you can manage as one logical CDB.

 

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Oracle Tidbits – March 2018 #oratidbit

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in March 2018. You will also see these tidbits 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 #db18c SQL*Plus Feature: The SET LINESIZE command has a WINDOW option to automatically change the linesize and pagesize for the formatted output according to the width and height of the screen.
#oratidbit #db18c SQL*Plus Feature: SQL_ID option for the SET FEEDBACK command displays the sql_id for the currently executed SQL or PL/SQL statements. The sql_id will be assigned to the predefined variable _SQL_ID.
#oratidbit #db18c Instead of terminating a session, you can cancel a high-load SQL statement in a session. When you cancel a DML statement, the statement is rolled back. Usie the ALTER SYSTEM CANCEL SQL statement.
#oratidbit #db18c An Oracle home can be read-only, thus preventing creation or modification of files inside the Oracle home directory ORACLE_HOME. A read-only Oracle home can be used as a software image that can be shared across multiple database servers.
#oratidbit #db18c The default location for Oracle Database password file (ORAPWD) is ORACLE_BASE directory instead of ORACLE_HOME directory. This change supports read-only Oracle homes.
#oratidbit #db18c When OPTIMIZER_IGNORE_HINTS parameter is set to TRUE, the optimizer ignores embedded hints.
#oratidbit #db18c When OPTIMIZER_IGNORE_PARALLEL_HINTS parameter is set to TRUE, the optimizer ignores embedded parallel hints.
#oratidbit #db18c To change the starting point of a sequence, use the RESTART clause to restart the sequence from the specified value. The new value specified must be between the MINVALUE and MAXVALUE parameter values.
#oratidbit #db18c New init parameter FORWARD_LISTENER specifies the name of a listener to which a connection must be forwarded by an existing set of remote listeners.
#oratidbit #db18c Private temporary tables are temporary database objects that are automatically dropped at the end of a transaction or a session. A private temporary table is stored in memory and is visible only to the session that created it.
#oratidbit #db18c Init parameters STANDBY_ARCHIVE_DEST and UTL_FILE_DIR are desupported in #orcldb 18.1.
#oratidbit Oracle Database Cloud Backup Module is an SBT interface integrated with RMAN. Database backups are created using RMAN and the Cloud Backup Module sends these backups, to Oracle Database Backup Service for offsite storage.
#oratidbit #db18c You can create both global temporary tables and private temporary tables on an Active Data Guard instance. DML and DDL operations are allowed on temporary tables on Oracle Active Data Guard instances.
#oratidbit #db18c A new view V$DATAGUARD_PROCESS provides information to verify that redo is being transmitted from the primary database and applied to the standby database.
#oratidbit The DROP TABLESPACE INCLUDING CONTENTS AND DATAFILES SQL statement on the primary database will delete the data files on (both the primary and) standby databases, if the STANDBY_FILE_MANAGEMENT init parameter is set to AUTO.
#oratidbit In order to use the EM Express Performance Hub ($ORACLE_HOME/rdbms/admin/perfhubrpt.sql), need the Diagnostics Pack license. To view SQL Monitor data in Performance Hub, need the Tuning Pack license.
#oratidbit #db18c Oracle Database software is available as an image file for download and installation. Extract the image software into the directory where the Oracle home to be located, and then run the runInstaller script to start the Oracle Database installation.
#oratidbit #db18c Starting with Oracle Database 18c, you can use the Oracle Preinstallation RPM and the rpm -ivh command to perform an RPM-based Oracle Database installation. RPM-based installation is supported for single-instance Oracle Database on Oracle Linux systems only.
#oratidbit #orcldb Deprecated features are no longer being enhanced, but are still supported. Desupported features are no longer supported by fixing bugs related to that feature. Oracle can choose to remove the code required to use the feature.
#oratidbit #db18c Oracle Database 18c is the terminal release for support of the Oracle Streams. Oracle Streams will be desupported from Oracle Database 19 onwards and was deprecated in Oracle Database 12c (12.1).
#ortidbit #db18c Support for the initialization parameter STANDBY_ARCHIVE_DEST is removed in Oracle Database 18c. For LOCAL and REMOTE archiving, use LOG_ARCHIVE_DEST_n.