Oracle 12c

12cR2 multitenant containers in SQL_TRACE

By Franck Pachot . In multitenant you session can switch between containers. For example, since 12.1, a common user can switch explicitly between CDB$ROOT and any PDB with the 'ALTER SYSTEM SET CONTAINER'. Any user connected to a PDB will(…)

Oracle 12cR2 multitenant: Local UNDO

By Franck Pachot . Pluggable Databases are supposed to be isolated, containing the whole of user data and metadata. This is the definition of dictionary separation coming with multitenant architecture: only system data and metadata are at CDB level. User(…)

Oracle 12cR2 PL/SQL new feature: TNSPING from the database

By Franck Pachot . Database links are resolved with the server TNS_ADMIN configuration (sqlnet.ora and tnsnames.ora). You can use tnsping to check the resolution, but it supposes that you are on the server and have set the same environment(…)

Oracle 12c – Difference between ‘%F’ #default and ‘%F’

By William Sescu Do you see any differences between these two RMAN SHOW commands? RMAN> SHOW CONTROLFILE AUTOBACKUP FORMAT; RMAN configuration parameters for database with db_unique_name OCM121 are: CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default(…)

Oracle 12c – Automatic Control File Backups

By William Sescu By default, automatic control file backups are disabled (even with 12c), maybe for performance reasons. RMAN> SHOW CONTROLFILE AUTOBACKUP; RMAN configuration parameters for database with db_unique_name OCM121 are: CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default And also good(…)

Oracle 12c – When the RMAN Dummy Instance does not start up …

By William Sescu Not too often, but sometimes you might run into a situation when you lose everything, your DB Files, your Controlfiles and even your spfile. In situations like that, you need to restore first your spfile, then your(…)

Oracle 12c – When did my row change?

By William Sescu My good old DEPT table always had 4 rows with 4 different departments. However, I have noticed that a new row was inserted into the DEPT table and the row 50 popped up, and I would like to(…)

12c GTT private statistics and cursor invalidation

By Franck Pachot . Short summary of this post is that rolling invalidation do not occur when you gather statistics on Global Temporary Tables in 12c that have session statistic scope (which is the default) and this may cause too(…)

Oracle 12c – Managing RMAN persistent settings via SQL

By William Sescu RMAN persistent settings can be managed in two different ways. Via the RMAN interface – e.g. RMAN> CONFIGURE BACKUP OPTIMIZATION ON; Via SQL – e.g. VARIABLE RECNO NUMBER; EXECUTE :RECNO := SYS.DBMS_BACKUP_RESTORE.SETCONFIG(‘BACKUP OPTIMIZATION’,’ON’); There(…)

Oracle 12c and RMAN switch datafile to copy, is it really so easy?

By William Sescu Oracle incrementally updating backups are used quite often because they are easy to setup and restoring a datafile is very fast. It is very fast because you are not really restoring a datafile, you are switching to(…)