oracle 12c

The Problem On Oracle database 12.2.0.1 version, cpu_count is not correct: OS has 128 CPU in total, however CPU_COUNT is only 104. SQL> show parameter cpu NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ cpu_count integer 104 … [Read more...] about Oracle Database 12c2 : CPU_COUNT is Wrong

In this release, a data file can now be moved online while it is open and being accessed, even for data files in system tablespace. Being able to move a data file online means that many maintenance operations, such as moving data to another storage device or moving databases into Oracle Automatic Storage Management (Oracle ASM), can be performed while users are accessing the system. This ensures that continuity of service and service-level agreements (SLA) on uptime can be met. With Oracle … [Read more...] about Oracle Database 12c New Feature – Move a Datafile Online

This post illustrates how to rename a database in 12.2 and then move the datafiles to another location online (given the DB name is changed, we expect the datafile are moved to another directory whose directory name is the new DB name). We will rename database from ORCL122 to CDB122, and move datafiles from /refresh/home/app/oracle/oradata/ORCL122/ to /refresh/home/app/oracle/oradata/CDB122/ 1. backup database. 2. set ORACLE_SID to ORCL122. 3. shutdown database, and then start it to … [Read more...] about How to rename database and then move datafile online in Oracle Database 12.2

Question: How to Restore Dropped PDB in Multitenant using Auxiliary instance ( For Single Instance Database)? In a multitenant container database (CDB), the metadata for data dictionary tables and view definitions is stored only in the root. However, each pluggable database (PDB) has its own set of data dictionary tables and views for the database objects contained in the PDB. So, a pluggable database (PDB) cannot be restored as a database. It must be restored as database object using an … [Read more...] about How to Restore a Dropped Pluggable Database (PDB) in Multitenant Environment

If flashback of CDB complete, there are chances to previously dropped PDB datafiles goes offline. There might be PDB dropped in past and now dropped PDB related datafiles becomes offline during flashback database. Example Backup of this database taken around scn 4700000. PDB3 was dropped at SCN 4800000. Flashback for CDB was complete until scn 4810629. Find the files those are offline (those are related to Dropped PDB i.e pdb3) sql> select file#,name from v$datafile; For this test, we … [Read more...] about How to Recover DROPPED PDB After Flashback of CDB

Before 12c there are only few commands available for startup and shutdown but if we follow that we may end up starting and stopping the PDBs and CDB as well. shutdown normal shutdown immediate shutdown abort startup startup nomount startup mount If we use one of these traditional shutdown methods at the container database (CDB) layer, we will bring down the CDB and the associated PDBs under it. This is something to be aware of when looking to reboot a container database. Let's take a … [Read more...] about When to Use Startup/Shutdown Database and Alter Database Command in Oracle 12c

Traditional startup/shutdown methods prior to 12c Traditional startup/shutdown command prior to 12c as as shown below. Shutdown Command SHUTDOWN NORMAL SHUTDOWN IMMEDIATE SHUTDOWN ABORT Startup Command STARTUP STARTUP NOMOUNT STARTUP MOUNT What happen when we execute shutdown immediate at CDB? If we use one of these traditional shutdown methods at the container database (CDB) layer, we will bring down the CDB and the associated PDBs under it. $ sqlplus / as sysdba SQL*Plus: … [Read more...] about How to Startup/Shutdown PDB’s in Oracle Database 12c