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.

Happy New Year 2018!

We all have questions on Oracle Database 18c and its ability to self-drive! I tried to summarize my understanding of Oracle Database 18c and RU/RUR in a blog post here.

What to expect in Oracle Database 18c

“Oracle Database 18c by itself is NOT Self-Driving. It is the Oracle Autonomous Database Cloud Service that brings the “Self-Driving” in 18c. Oracle Database 18c installed on-prem will “drive” pretty much the same as Oracle Database 12c.”

I like the idea of releasing major features more frequently and releasing patches and updates that are smaller in size and easy to test. But, the question still is how many DBAs out there are ready to patch every quarter, even if you are able to automate the patching using OEM and other tools.

Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in December 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 #db12cR2 Credentials created using the DBMS_CREDENTIAL.CREATE_CREDENTIAL procedure are database objects that hold a username/password pair for authenticating and impersonating EXTPROC callout functions, remote jobs, external jobs and file watchers from the SCHEDULER.
#oratidbit #orcldb Oracle Advanced Queuing stores user messages in abstract storage units called queues. When business applications communicate with each other, producer applications enqueue messages and consumer applications dequeue messages.
#oratidbit #orcldb XStream consists of Oracle Database components and application programming interfaces (APIs) that enable client applications to receive data changes from an Oracle database and send data changes to an Oracle database.
#oratidbit #db12cR2 Init parameter ASM_IO_PROCESSES in 12.2 specifies the number of I/O worker processes to be started in an Oracle Automatic Storage Management (Oracle ASM) IOServer instance.
#oratidbit #db12cR2 Init parameter ENABLE_AUTOMATIC_MAINTENANCE_PDB in 12.2 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 #db12cR2 In 12.2 Oracle Multitenant license allows 252 PDBs in Enterprise Edition and 4096 PDBs in EE on Exadata.
#oratidbit #db12cR2 When the character set of the CDB root is AL32UTF8, any container in the CDB canSharding is a data tier architecture in which data is horizontally partitioned across independent databases. use a character set that is different from the CDB root and different from other containers in the CDB.
#oratidbit A proxy PDB provides access to another PDB in a remote CDB. Use the CREATE PLUGGABLE DATABASE statement to create a proxy PDB by referencing the other PDB. Use a proxy PDB when you want a local context for a remote PDB.
#oratidbit #db12cR2 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 PDBs.
#oratidbit #orcldb database acquires a full table lock on the child table when no index exists on the foreign key column of the child table, and a session modifies a primary key in the parent table.
#oratidbit #Sharding is a data tier architecture in which data is horizontally partitioned across independent databases. Sharding provides linear scalability and complete fault isolation for the most demanding OLTP applications.
#oratidbit In Oracle Database 12c Release 1 (12.2.0.1) all shards and shard catalog must be non-CDB databases.
#oratidbit #db12cR2 Use the new -R option for the parallel upgrade utility (catctl.pl) to resume the upgrade at the point of failure, so that only the missing upgrade phases are rerun – Automatic Resume After Failed Upgrades feature.
#oratidbit #db12cR2 Use the new -T option for the parallel upgrade utility (catctl.pl) to set user tablespaces automatically to READ-ONLY during an upgrade. After the upgrade, the tablespaces are changed back automatically to READ/WRITE.
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