“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. |