Author: Biju

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in February 2018. 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 #oraclecloud Oracle Database Backup Cloud Service includes two Oracle Database optimizations – RMAN backup encryption and All RMAN backup compression algorithms.

#oratidbit #oraclecloud Oracle Database Backup Cloud Service is used to store Oracle Database backups only. To store other types of data, use Oracle Storage Cloud Service.

#oratidbit #oraclecloud Oracle DBaaS Monitor provides monitoring and management of the Oracle database and listener on Oracle Database Cloud Service. To use the Open DBaaS Monitor Console menu item, you must unblock port 443.

#oratidbit #oraclecloud Deployments that host single-instance databases include the cleandblogs cronjob script to archive and purge a variety of log and diagnostic files. Config file cleandblogs.cfg determines how long to retain each kind of log or diagnostic file.

#oratidbit #oraclecloud Oracle Database Cloud Service Data Guard configuration can be administered using the dbaascli utility. “dbaascli dataguard” command options include “status”, “failover”, “switchover”, “reinstate”.

#oratidbit #oraclecloud Use the “dbpatchmsm” utility to apply Linux OS security patches to compute nodes associated with database deployments hosting a single-instance database.

#oratidbit #oraclecloud Use the “dbpatchm” subcommand of the “dbaascli” utility to apply a patch to a database deployment hosting a single-instance database.

#oratidbit The DBMS_SQLTUNE package is the interface for tuning SQL on demand. The DBMS_AUTO_SQLTUNE package provides the interface for SQL Tuning Advisor run as an automated task.

#oratidbit The automated system task SYS_AUTO_SQL_TUNING_TASK automatically chooses a set of high-load SQL from AWR and runs SQL Tuning Advisor. The automated task performs the same comprehensive analysis as any other SQL Tuning task.

#oratidbit Oracle Database SQL Monitor will only monitor a SQL statement if the execution plan has less than 300 lines. Set the underscore parameter _sqlmon_max_planlines to increase this limit.

#oratidbit OPTIMIZER_DYNAMIC_SAMPLING value when set to 11, the optimizer will automatically determine which statements

would benefit from dynamic statistics, even if all of the objects have statistics.

#oratidbit The SQL Plan Management (SPM) Evolve Advisor is an AutoTask (SYS_AUTO_SPM_EVOLVE_TASK), which operates during the nightly maintenance window and automatically runs the evolve process for unaccepted plans in SPM.

#oratidbit #db18c Zero-Downtime Database Upgrade automates all of the steps required for a Database upgrade. It can minimize or even eliminate application downtime during the upgrade process.

#oratidbit #db18c Passwords in database links are encrypted in 18c. Oracle Data Pump handles the export and import of these passwords. This prevents an intruder from decrypting an encrypted database link password.

#oratidbit #db18c A refreshable clone PDB is an incrementally updated copy of a master PDB. The new switchover feature enables a change of roles between master and clone PDBs for planned or unplanned switchover.

#oratidbit #db18c When you perform the export or import operation of a database, the unified audit trail is automatically included in the Data Pump dump files.

#oratidbit #db18c ASM database cloning provides cloning of Multitenant databases (PDBs) by leveraging ASM redundancy. Flex Disk Groups can provide up to five redundant copies, one or more of the copies can be split off to provide a near instantaneous replica.

#oratidbit $db18c Drop a file group and its associated files (drop including content) using the CASCADE keyword with ALTER DISKGROUP … DROP FILEGROUP SQL statement.

#oratidbit #ORAchk new version 12.2.0.1.4 works on Windows! It is rewritten in Python, no longer has the need for Cygwin on Windows. ORAchk just needs Python 2.7 software and libraries.

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in January 2018. 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 Adaptive Execution Plans, SQL Plan Management and several performance features are not available in #orcldb Standard Edition.

#oratidbit Automatic Block Repair, Global Data Services, Oracle Data Guard Far Sync Standby, Real-Time Cascading Standby configurations require Enterprise Edition with Active Data Guard option.

#oratidbit To monitor Oracle Database 12c Release 2 (12.2), you must be on EM 12c PS4 with Bundled Patch 2 or later applied. The EM agent that is used to monitor the database must be an EM 12c PS4 agent with Agent Bundled Patch 3 or later applied.

#oratidbit You can use Oracle Cloud Infrastructure FastConnect Classic to access your Oracle Cloud services using a direct connection from your premises or colocation facilities. You can also configure a VPN connection to your multitenant or dedicated Compute Classic site.

#oratidbit Oracle Database Cloud – Database Schema Service includes a schema in Oracle 11gR2 EE DB running on Exadata, APEX, RESTful Web Services & Packed Applications Sample Code.

#oratidbit The PGA_AGGREGATE_LIMIT parameter enables to specify an absolute limit on the PGA memory usage. If the value is exceeded, Oracle DB aborts or terminates the sessions or processes consuming the most untunable PGA memory.

#oratidbit In #db12cR2, you can take an AWR snapshot at a CDB-level (on a CDB root) or at a PDB-level (individual PDB). The CDB-level snapshot data is stored in the SYSAUX tablespace of a CDB root. The PDB-level snapshot data is stored in the SYSAUX tablespace of a PDB.

#oratidbit #db12cR2 The AWR_ROOT views are equivalent to the DBA_HIST views that show the AWR data present only on the CDB root. When the AWR_ROOT views are accessed from a PDB, they show the subset of the CDB root AWR data, which is specific to that PDB.

#oratidbit #db12cR2 The AWR_PDB views show the local AWR data present on a CDB root or a PDB. When accessed from a CDB root, they show the AWR data stored on the CDB root. When accessed from a PDB, they show the AWR data stored on that PDB.

#oratidbit Set an absolute limit on the amount of PGA memory that can be allocated to each session in a particular consumer group using the SESSION_PGA_LIMIT parameter of the DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE procedure of the Oracle Database Resource Manager.

#oratidbit Oracle DB can prespawn foreground processes to improve the performance of client connections. A prespawned process refers to a process that has been spawned but does not have a session yet. Procedures in the DBMS_PROCESS package can configure, start and stop a pool.

#oratidbit The version of the RMAN recovery catalog schema must be greater than or equal to the version of the RMAN client. The version of the RMAN client must be equal to the version of the target database.

#oratidbit The number of LONG type columns in a table is limited. Any given table can have a maximum of only one LONG type column. The number of LOB type columns in a table is not limited.

#oratidbit #db12cR2 Initialization parameter DATA_GUARD_SYNC_LATENCY, helps to define the maximum amount of time (in seconds) that the primary database may wait before disconnecting subsequent standby destinations after at least one synchronous standby has acknowledged receipt of the redo.

#oratidbit You can use the ALTER TABLE statement in SQL to convert a LONG column to a LOB column. The ALTER TABLE statement copies the contents of the table into a new space, and frees the old space at the end of the operation.

#oratidbit In Oracle #DB12cR2 many datatype conversion functions (TO_DATE TO_NUMBER etc) and CAST function includes data error handling using the “DEFAULT value ON CONVERSION ERROR” option. Example: TO_NUMBER(‘2,00’ DEFAULT 0 ON CONVERSION ERROR) returns 0 instead of error.

#oratidbit #DB12cR2 During a PDB clone operation, the source PDB no longer needs to be in read-only mode.

#oratidbit #DB12cR2 You can 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 PDB.

#oratidbit #DB12cR2 You can capture Automatic Workload Repository (AWR) data for Oracle Active Data Guard standby databases. This feature enables performance tuning of Oracle Active Data Guard standby databases.

#oratidbit Starting with #db12cR2 release, you can use the INACTIVE_ACCOUNT_TIME profile parameter to automatically lock the account of a database user who has not logged in to the database instance in a specified number of days.

#oratidbit #oraclecloud “Oracle Database Cloud Service – Virtual Image” is a compute environment with pre-installed virtual machine images that include all software needed to create and run an Oracle Database. Connect to the VM and run DBCA to create a database.

#oratidbit #oraclecloud The “Data Guard Standby for Hybrid DR” DBaaS cloud service type is a single-instance database acting as the standby database in an Oracle Data Guard configuration. The primary database is on your own system.

#oratidbit #oraclecloud The “Database Clustering with RAC and Data Guard Standby” DBaaS cloud service type includes two two-node Oracle RAC databases, one acting as the primary database and one acting as the standby database in an Oracle Data Guard configuration.