Oracle Tidbits – January 2018 #oratidbit

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.

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