Oracle Tidbits – August 2018 #oratidbit

Oracle *daily* TidBits” (#oratidbit) published on  FacebookTwitter, 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.