Oracle Tidbits – February 2019 #oratidbit

Oracle *daily* TidBits” (#oratidbit) published on Facebook & Twitter, during weekdays in February 2019. Hope you find these helpful to learn something new or to remind you of its existence and use.

#oratidbit In Oracle Database 18c, RMAN can recover a standby database using “FROM SERVICE” to perform an Active Data Guard synchronization and refresh the standby DB with a single RMAN command: RECOVER STANDBY DATABASE FROM SERVICE primary_db.
#oratidbit The LISTAGG aggregate function in #db19c supports duplicate elimination by using the DISTINCT keyword. With the new DISTINCT keyword, duplicate values can be removed from the specified expression before concatenation into a single string.
#oratidbit #db19c contains a keenly awaited fix to the optimizer costing for for ANSI fetch first/offset queries. Now they can take advantage of an index scan + stopkey as per the older style order by/rownum syntax.
#oratidbit #db18c New routine validate_character_encoding in UTL_I18N allow for validation of characters within a particular characterset.
#oratidbit #db18c The TREAT … as JSON operator provides a way to inform the database that the content of a VARCHAR2, BLOB, CLOB should be treated as containing JSON. This enables the ability to use “Simplified Syntax” on db objects that do not have an “IS JSON” constraint.
#oratidbit #db18c A scalable sequence adds a 6 digit prefix to the sequence. The prefix is made up of a 3 digit instance offset concatenated to a 3 digit session offset.
#oratidbit #thinkautonomous Oracle GoldenGate On Premises releases and later are certified with Oracle Autonomous Cloud for remote delivery using the non-integrated Replicats. You can’t set up Autonomous Cloud database as a source for GoldenGate On Premises.
#oratidbit Oracle Enterprise Manager Cloud Control releases 13.1 and 13.2 support integration with Oracle ORAchk and Oracle EXAchk through the OEM ORAchk Healthchecks Plug-in.
#oratidbit Each database PSU/RU contains the latest Oracle ORAchk version available at time of creation. When a database PSU is applied, the ORAchk zip version contained is staged in $ORACLE_HOME/suptools.
#oratidbit Oracle ORAchk and Oracle EXAchk include full REST support allowing invocation and query over HTTPS. To enable REST, setup ORDS and then provide a user password when prompted “orachk -ordssetup”.
#oratidbit #db19c Most of the Oracle Database supplied user accounts, except SYS and sample schemas are schema only accounts in 19c, these accounts are created without passwords. This prevents malicious users from logging into these accounts.
#oratidbit #db19c The automatic indexing feature automates index management tasks, such as creating, rebuilding, and dropping indexes in an Oracle database based on changes in the application workload.
#oratidbit In #db19c you can configure quarantine for execution plans for SQL statements that are terminated by the Resource Manager due to their excessive consumption of system resources, such as CPU and I/O. The quarantined execution plans are not allowed to run again.
#oratidbit #db19c. A hybrid partitioned table is a partitioned table in which some partitions reside in the database and some partitions reside outside the database in external files, such as operating system files or Hadoop Distributed File System (HDFS) files.
#oratidbit #db19c The new SQL Repair Advisor function DBMS_SQLDIAG.SQL_DIAGNOSE_AND_REPAIR creates a diagnostic task, executes it, and accepts SQL patch recommendation for a SQL statement that is generating a critical error.
#oratidbit #db19c The script catpcat.sql runs the scripts catalog.sql and catproc.sql with parallel processes, thus improving the performance of building the data dictionary manually.
#oratidbit The #db19c view DBA_REGISTRY_BACKPORTS shows the bugs that have been fixed by the patches applied to the database. Only the bug fixes that have modified the data dictionary are displayed in this view.
#oratidbit #db19c The LISTAGG aggregate function supports duplicate elimination by using the new DISTINCT keyword.
#oratidbit #db19c The standby database is flashed back automatically when Flashback Database is performed on the primary database. If you do not want the standby to automatically follow the primary, either keep the standby database in OPEN mode or stop the MRP process on the standby.
#oratidbit #db19c The ALTER SYSTEM clause FLUSH PASSWORDFILE_METADATA_CACHE refreshes the metadata cache with the latest details of the database password file. The latest details of the database password file can be retrieved by querying the V$PASSWORDFILE_INFO view.

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