Oracle Tidbits – September 2014

Oracle *daily* TidBits” published at https://www.facebook.com/oraclenotes on all weekdays in September 2014. 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…

Publish Date TidBit
3-Sep In 12.1.0.2, the CREATE INDEX has a new clause COMPRESS ADVANCED LOW to enable advanced index compression. Advanced index compression improves compression ratios significantly.
4-Sep In 12.1.0.2, the ALTER DATABASE statement has a new clause FORCE FULL DATABASE CACHING to enable the force full database caching mode. The force full database caching mode considers the entire database, including NOCACHE LOBs, as eligible for caching in the buffer cache.
2-Sep READ object privilege available from 12.1.0.2 version of 12c database is an alternative to SELECT privilege. With SELECT privilege, you can lock the rows using the LOCK TABLE and SELECT … FOR UPDATE statements, with READ locking of rows is not possible.
5-Sep The READ ANY TABLE system privilege is an alternative to the SELECT ANY TABLE system privilege. In addition to querying objects, the SELECT ANY TABLE privilege allows users to lock rows of a table with the SELECT … FOR UPDATE statement. The READ ANY TABLE privilege only allows users to query objects.
8-Sep New COMMON_USER_PREFIX parameter: A common user in a multitenant database is a database user that has the same identity in the root and in every existing and future PDB. Every common user can connect to and perform operations within the root, and within any PDB in which it has privileges. The common user is created in the root container and must begin with C## in version 12.1.0.1. From 12.1.0.2 onwards, you can set the prefix characters by using the intialization parameter COMMON_USER_PREFIX.
10-Sep The DBMS_STATS.REPORT_GATHER_*_STATS functions can be used to run statistics gathering procedures in reporting mode. In this case, the optimizer does not actually gather statistics, but reports objects that would be processed if you were to use a specified statistics gathering function. The output can be in XML, HTML or TEXT format.
12-Sep The DBMS_STATS.REPORT_STATS_OPERATIONS function generates a report of all statistics operations that occurred between two points in time. You can narrow the scope of the report to include only automatic statistics gathering runs.
15-Sep In Oracle Database 12c, the catupgrd.sql Upgrade Utility has been replaced with the catctl.pl Parallel Upgrade Utility. You can run upgrade scripts and processes in parallel, taking full advantage of CPU capacity and shortening the upgrade time. By default DBUA runs in parallel upgrade mode.
17-Sep The emremove.sql script drops the Oracle Enterprise Manager-related schemas and objects. Use this script to manually remove EM DB Control during upgrade of pre-12c databsae to 12c. Running emremove.sql before starting the upgrade process minimizes upgrade downtime, as it is required to drop EM during 12c upgrade. DB Control is replaced with EM Express in 12c.
19-Sep When upgrading Oracle database, DBUA (in 11gR2 and 12c) expects that both the source (pre-upgrade) Oracle home and the destination (newly upgraded) Oracle home are owned by the same user.
23-Sep The AUDSYS internal database user owns the unified audit trail information in Oracle Database 12c. The audit information is queryable using the read only view UNIFIED_AUDIT_TRAIL.
25-Sep In Oracle Database 12c, there can be up to 100 Database Writer Processes (configured using DB_WRITER_PROCESSES parameter). The names of the first 36 Database Writer Processes are DBW0-DBW9 and DBWa-DBWz. The names of the 37th through 100th Database Writer Processes are BW36-BW99.

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