Oracle Tidbits – August 2017 #oratidbit

Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in July 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 If you are installing 64-bit Oracle Database software, and your existing Oracle Database is a 32-bit Oracle Database installation, then your existing Oracle Database is automatically converted to 64-bit during the upgrade.
#oratidbit You can install Oracle R Enterprise Server in a pluggable database (PDB) within a multitenant container database (CDB). The database may not be the root database.
#oratidbit An external procedure is a procedure invoked from a program that is written in a different language. Oracle Database uses an external procedure agent named extproc to support external procedures.
#oratidbit #orcldb #datapump Setting the parameter _OPTIMIZER_GATHER_STATS_ON_LOAD=FALSE might improve the table loading speed. Use this parameter if you include EXCLUDE=STATISTICS, and plan to collect stats after the import.
#oratidbit ROracle is an open source R package that enables interaction between R and an Oracle database. ROracle is maintained and supported by Oracle. ROracle is licensed under LGPL v.2 or later and not under the terms of your Oracle license agreement.
#oratidbit #db12cR2 SQL92_SECURITY initialization parameter default is TRUE in 12.2. Meaning, users must have been granted the SELECT object privilege in order to execute UPDATE or DELETE statements.
#oratidbit Parallel upgrade utility in 12c is catctl.pl. In #db12cR2 use the dbupgrade (Linux/Unix) or dbupgrade.cmd (Windows) shell script instead of using catctl.pl.
#oratidbit Oracle ASM Filter Driver (Oracle ASMFD) is a kernel module that resides in the I/O path of the Oracle ASM disks. Oracle ASM uses the filter driver to validate write I/O requests to Oracle ASM disks and rejects any I/O requests that are invalid.
#oratidbit Oracle ASM disk scrubbing checks logical data corruptions and repairs the corruptions automatically in normal and high redundancy disks groups. The feature is designed so that it does not have any impact on the regular input and output (I/O) operations in production systems.
#oratidbit Automatic memory management is enabled by default on an Oracle ASM instance, even when the MEMORY_TARGET parameter is not explicitly set.
#oratidbit #orcldb A proxy PDB is a PDB that uses a database link to reference a PDB in a remote CDB. When you issue a statement in a proxy PDB while the PDB is open, the statement executes in the referenced PDB.
#oratidbit #orcldb GV$AQ_MESSAGE_CACHE_ADVICE provides advice on how much STREAMS_POOL should be allocated for sharded queues based on a snapshot of the current messaging load.
#oratidbit A subset of GDSCTL commands are applicable to Global Data Services (GDS) configuration and another subset of GDSCTL commands are for Oracle Sharding configuration.
#oratidbit chactl commands are to administer Oracle Cluster Health Advisor basic monitoring functionality on the RAC targets.
#oratidbit The Trace File Analyzer control utility, TFACTL, is the command-line interface for Oracle Trace File Analyzer. You need root access or sudo access to tfactl to run administration commands.
#oratidbit #db12cR2 After installing 12.2.0.1 database a pre-existing database link SYS_HUB exists as a requirement to clone a remote PDB.
#oratidbit #orcldb The SPARE6 column in SYS.USER$ table keeps track the last successful login time of the user in Oracle Database 12c. This is a very good security feature, without enabling “AUDIT SESSION” to find when the user last used the database.
#oratidbit #orcldb In Oracle Database 12c, when you move the online data file using ALTER DATABASE MOVE DATAFILE ‘filename’; without the TO clause, the file will be moved to DB_FILE_CREATE_DEST as Oracle Managed File – the DB_FILE_CREATE_DEST location can be ASM diskgroup or file system.
#oratidbit #orcldb Oracle Database 12c has new CASCADE clause for TRUNCATE statement. This truncates all child tables that reference the truncated table if the foreign key is defined with ON DELETE CASCADE option and the FK constraint is in ENABLED status. Children, grand children are truncated.
#oratidbit #db12cR2 The DBMS_DEBUG package is deprecated in Oracle Database 12c release 2 (12.2). Use DBMS_DEBUG_JDWP instead.
#oratidbit #db12cR2 DBUA in Database 12cR2 has priority-based PDB upgrades. You can set priority for PDB upgrades so that higher priority PDBs are upgraded first.
#oratidbit #db12cR2 The DBMS_JOB package is deprecated and may be unsupported in a future release. Use DBMS_SCHEDULER instead.
#oratidbit #db12cR2 DBUA in Database 12cR2 has Standalone Prerequisite Checks: You can run DBUA with the -executePrereqs option to check prerequisites for upgrades at any time.

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