Oracle 12c

ORACLE 11g to 12c RMAN catalog migration

This is a small migration demo of a 11g catalog (RCAT11G) to a new 12c catalog (RCAT12c). Demo databases environments have been easily managed thanks to DBI DMK tool. oracle@vmreforadg01:/home/oracle/ [RCAT11G] sqh SQL*Plus:(…)

Automatic Data Optimization Part I : Compression Tiering

By Mouhamadou Diaw Nowadays data are increasing more and more. And some challenges we can face can be how to reduce storage costs and how to improve performance. With Oracle 12c, the feature Automatic Data Optimization (ADO) can help us.

Keep your orapw password file secure

By Franck Pachot . This is a small demo I did when I've found a database password file (orapw) lying around in /tmp with -rw-rw-rw- permissions, to show how this is a bad idea. People think that the orapw file(…)

12c Multitenant internals: PDB_PLUG_IN_VIOLATIONS

By Franck Pachot . In the previous post https://www.dbi-services.com/blog/12c-multitenant-internals-pdb-replay-ddl-for-common-users I've done some DDL on a common user to show how this is replayed later for PDBs that were not opened at that time. But what happens(…)

12c Multitenant internals: PDB replay DDL for common users

By Franck Pachot . In multitenant, you can create common Users, Roles, and Profiles. You create them in CDB$ROOT, with the CONTAINER=ALL clause (which is optional because it is the only possible value when connected to CDB$ROOT) but they are(…)

Drop PDB including datafiles may keep files open

By Franck Pachot . I like that Oracle drops the datafiles from the operating system when we remove them from the database (with drop tablespace or drop pluggable database) because I don't like to have orphean files remaining in the(…)

12cR2 Subquery Elimination

By Franck Pachot . More and more we can see crazy queries generated by ORM frameworks or BI query generators. They are build to be easily generated rather than being optimal. Then, the optimizer has to implement more and more(…)

Naming of archivelog files with non existing top level archivelog directory

In Oracle 12.2 an archive log directory is accepted, if top level directory does not exist: oracle@localhost:/u01/app/oracle/product/12.2.0/dbhome_1/dbs/ [DMK] ls -l /u02/oradata/DMK/ total 2267920 drwxr-xr-x. 2 oracle dba        96 Dec  6 05:36 arch ... Now database accepts(…)

impdp logtime=all metrics=y and 12cR2 parallel metadata

By Franck Pachot . A quick post to show why you should always use LOGTIME=ALL METRICS=Y when using Data Pump. Just look at an example showing the timestamp in front of each line and a message about each task completed(…)

12c Multitenant Internals: compiling system package from PDB

By Franck Pachot . When I explain the multitenant internals, I show that all metadata about system procedures and packages are stored only in CDB$ROOT and are accessed from the PDBs through metadata links. I take an example with(…)