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
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How to rename database and then move datafile online in Oracle Database 12.2
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
New Background Processes In Oracle 11g
This post provides information on new background processes introduced in 11g. ACMS (atomic controlfile to memory service) This per-instance process is an agent that contributes to ensuring a distributed SGA memory update is either globally committed on success or globally aborted in the event of a failure in an Oracle RAC environment. DBRM (database resource manager) This process is responsible for setting resource plans and other resource manager related tasks. DIA0 (diagnosability … [Read more...] about New Background Processes In Oracle 11g
How to Restore a Dropped Pluggable Database (PDB) in Multitenant Environment
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
How to Recover DROPPED PDB After Flashback of CDB
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
Oracle RMAN 11g New Feature – MultiSection Backups
What are MultiSection Backups? By default, RMAN uses the parameters like filesize and number of available channels to decide whether to produce a single or multidatafile backupset with 1 or more backuppieces. In a multisection backup, RMAN creates a backup set in which each backup piece contains the blocks from one datafile section. A file section is a contiguous range of blocks in a datafile. The purpose of multisection backups is to enable RMAN to back up a single file in parallel. RMAN … [Read more...] about Oracle RMAN 11g New Feature – MultiSection Backups
Oracle 11G RMAN – Understanding UNDO backup optimisation
In backup undo optimization, RMAN excludes undo not needed for recovery from the backup, that is, for transactions which have already been committed. For example, a user updates the salaries table in the USERS tablespace. The change is written to the USERS tablespace, while the before image of the data is written to the UNDO tablespace. The user commits. A subsequent RMAN backup of the UNDO tablespace does not include the undo information for the salary changes as a restore of this backup would … [Read more...] about Oracle 11G RMAN – Understanding UNDO backup optimisation
RMAN ‘Duplicate From Active Database’ Feature in Oracle 11g
You can create a duplicate database using the RMAN duplicate command. The duplicate database has a different DBID from the source database and functions entirely independently.Starting from 11g you can do duplicate database in 2 ways. Active database duplication Backup-based duplication Active database duplication copies the live target database over the network to the auxiliary destination and then creates the duplicate database. The only difference is that you don't need to have the … [Read more...] about RMAN ‘Duplicate From Active Database’ Feature in Oracle 11g
Oracle 11g New Feature – Archived Redo Log Failover
Prior to 11g, if an archived log is corrupt in the FRA then RMAN command BACKUP RECOVERY AREA command will fail, even though the log has been archived to both the FRA and to a local archivelog destination. Truncated log (10G): ORA-19625: error identifying file D:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\TEST\ARCHIVELOG\2007_10_29\O1_MF_1_23_3LBZC64C_.ARC ORA-27046: file size is not a multiple of logical block size OSD-04012: file size mismatch Missing log (10G): RMAN-03002: failure … [Read more...] about Oracle 11g New Feature – Archived Redo Log Failover
How To Change A Dictionary Managed Tablespace To A Locally Managed Tablespace
Question: How to migrate Dictionary Managed Tablespace (DMT) to a Locally Managed Tablespace (LMT) using DBMS_SPACE_ADMIN.TABLESPACE_MIGRATE_TO_LOCAL procedure? Warning: It is highly recommended to test the steps in similar test environment to have an estimate of the time required for migration before implementing in Production. You can use the DBMS_SPACE_ADMIN.TABLESPACE_MIGRATE_TO_LOCAL procedure to migrate a tablespace from dictionary managed to locally managed. Perform the following … [Read more...] about How To Change A Dictionary Managed Tablespace To A Locally Managed Tablespace