OracleNotes

Category: TidBits

  • Oracle Tidbits – September 2018 #oratidbit

    Oracle Tidbits – September 2018 #oratidbit

    “Oracle *daily* TidBits” (#oratidbit) published on  Facebook, Twitter, and Google+ during weekdays in September 2018. Hope you find these helpful to learn something new or to remind you of its existence and use.

    #oratidbit #license SQL Plan Management in Standard Edition- Only one SQL plan baseline per SQL statement is allowed and SQL plan evolution is disabled.
    #oratidbit #license Oracle Sharding – no limit on the number of either primary shards or standby shards if every shard has an Oracle Active Data Guard, Golden Gate, or Oracle RAC license. Without these, use is limited to three primary shards.
    #oratidbit #license Tablespace encryption is not available on Standard Edition (SE2) on-prem, but is included in the DBCS-SE (Oracle Database Cloud Service Standard Edition) offering.
    #oratidbit Oracle Personal Edition includes all of the components that are included with Enterprise Edition, as well as all Oracle Database options except Oracle RAC. Oracle management packs cannot be used with Personal Edition.
    #oratidbit You can enable or disable a CBO related bug fix using the _FIX_CONTROL parameter – gives granular control over specific features and bug fixes. Use V$SYSTEM_FIX_CONTROL to see what bug fix is implemented and detail.
    #oratidbit The CDB_* views can be queried only by users with the SYSDBA system privilege or SELECT ANY DICTIONARY privilege, or SELECT_CATALOG_ROLE role, or by users with direct privileges granted to them.
    #oratidbit CDB_* views include these hidden columns: CON$NAME: the name of the container whose data a given CDB_* row represents. CDB$NAME: the name of the CDB whose data a given CDB_* row represents.
    #oratidbit The AWR_ROOT_* views show the AWR data stored only on a CDB root. In general, the AWR_ROOT views are equivalent to the DBA_HIST views.
    #oratidbit A connection storm is a race condition in which application servers initiate an increasing number of connection requests, but the database server CPU is unable to schedule them immediately, which causes the application servers to create more connections.
    #oratidbit Database Resident Connection Pool (DRCP) provides a connection pool in the database server for typical web application usage scenarios where the application acquires a database connection, works on the database for a relatively short time, and then releases the connection.
    #oratidbit Database Resident Connection Pool (DRCP) is installed by default, but the DBA must start, and configure it using the DBMS_CONNECTION_POOL package.
    #oratidbit When Database Resident Connection Pool (DRCP) is configured in a database in an Oracle RAC environment, the pool configuration is applied to each database instance. Starting or stopping the pool on one instance starts or stops the pool on all instances.
    #oratidbit The Memoptimize Pool optimizes the read operation for select statements. Memoptimize Rowstore performs high-performance reads for tables specified with the MEMOPTIMIZE FOR READ clause.
    #oratidbit DBCA (Database Configuartion Assistant) enables you to create and duplicate CDBs, and create, clone, plug in, and unplug PDBs.
    #oratidbit #OEM13c You can upgrade only 13c Release 2 (13.2.0.0), 13c Release 1 (13.1.0.0), or 12c Release 5 (12.1.0.5) directly to 13c Release 3 (13.3.0.0).
    #oratidbit Oracle Data Mining supports both supervised and unsupervised data mining. The DBMS_DATA_MINING package is the application programming interface for creating, evaluating, and querying data mining models.
    #oratidbit A transformation is a SQL expression that modifies the data in one or more columns. The DBMS_DATA_MINING_TRANSFORM package implements a set of transformations that are commonly used in data mining.
    #oratidbit Oracle R Enterprise is a component of the Oracle Advanced Analytics Option of Oracle Database Enterprise Edition. Oracle R Enterprise is comprehensive, database-centric environment for end-to-end analytical processes in R.
  • Oracle Tidbits – August 2018 #oratidbit

    Oracle Tidbits – August 2018 #oratidbit

    “Oracle *daily* TidBits” (#oratidbit) published on  Facebook, Twitter, and Google+ during weekdays in August 2018. Hope you find these helpful to learn something new or to remind you of its existence and use.

    #oratidbit When the value of UNIFORM_LOG_TIMESTAMP_FORMAT init parameter is FALSE, trace files include a mix of timestamps using different precisions, with some timestamps showing local time and other timestamps showing universal time.
    #oratidbit USE_LARGE_PAGES init parameter is used to manage the database’s use of large pages for SGA memory. Value ONLY specifies that the instance will fail to start if large pages cannot be used for the entire SGA memory.
    #oratidbit MAX_MBPS init parameter enables you to set the maximum number of megabytes (MB) of I/Os issued per second on a per pluggable database (PDB) basis. This parameter is used to throttle PDB I/Os.
    #oratidbit Oracle Autonomous Transaction Processing (ATP) Cloud Service includes database migration utility to easily migrate from MySQL, PostgreSQL, SQL Server, and other databases.
    #oratidbit Oracle Autonomous Transaction Processing (ATP) automatically backs up your database. The retention period for backups is 60 days. You can restore and recover your database to any point-in-time in this retention period.
    #oratidbit In Oracle Autonomous Transaction Processing (ATP) the default data and temporary tablespaces for the database are configured automatically. Adding, removing, or modifying tablespaces is not allowed.
    #oratidbit In Oracle Autonomous Transaction Processing (ATP) database links to other databases are not allowed for enhanced security. Database links from other databases to ATP are allowed.
    #oratidbit In Oracle Autonomous Transaction Processing (ATP) a few initialization parameters can be modified, including OPTIMIZER_IGNORE_HINTS and OPTIMIZER_IGNORE_PARALLEL_HINTS.
    #oratidbit In Oracle Autonomous Transaction Processing (ATP) LONG and LONG RAW data types are not supported.
    #oratidbit #atp you can configure Autonomous Transaction Processing to terminate SQL statements automatically based on their runtime or the amount of IO they are doing. Use the procedure cs_resource_manager.update_plan_directive to set these rules.
    #oratidbit With centrally managed users (CMU) Oracle database users and roles can map directly to Active Directory users and groups without using Oracle Enterprise User Security (EUS) or another intermediate directory service.
    #oratidbit #db18c Setting ADG_ACCOUNT_INFO_TRACKING to GLOBAL maintains a single global copy of users account information across all Data Guard databases (primary and standby). Login failures across all databases count towards the maximum count and logins anywhere will be denied when the count is reached.
    #oratidbit Init parameter PARALLEL_DEGREE_LIMIT limits the degree of parallelism used by the optimizer to ensure that parallel server processes do not flood the system.
    #oratidbit Init parameter RESOURCE_MANAGE_GOLDENGATE determines whether Oracle GoldenGate apply processes in the database are resource managed. By default, Oracle GoldenGate apply processes in the database are not resource managed.
    #oratidbit Init parameter PDB_OS_CREDENTIAL determines the identity of the OS user employed when interacting with the OS from a PDB. Helps ensure that OS interactions are by a less powerful user and protects data belonging to one PDB from being accessed by users connected to another PDB.
    #oratidbit #ATP The tnsnames.ora file provided with the credentials zip file contains four database service names as high, medium , low, and parallel. The predefined service names provide different levels of performance and concurrency for ATP Cloud Service.
    #oratidbit Hash partitioned global indexes can improve the performance of indexes where a small number of leaf blocks in the index have high contention in multiuser OLTP environments.
    #oratidbit The awrgdrpi.sql SQL script generates an HTML or text report that compares detailed performance attributes and configuration settings between two selected time periods using specific databases and instances in an Oracle RAC environment.
    #oratidbit The ashrpti.sql SQL script generates an HTML or text report that displays ASH information for a specified duration for specified databases and instances in an Oracle Real Application Clusters (Oracle RAC) environment.
    #oratidbit V$RSRC_CONSUMER_GROUP shows CPU utilization statistics for each consumer group when the Oracle Database Resource Manager is running.