This post discusses a few 12C ASM new features with examples: Failgroup_repair_time Online disk replace Estimate Work V$ASM_OPERATION view 1. FAILGROUP_REPAIR_TIME For earlier ASM versions, we had disk_repair_time, from 12C onwards we have failgroup_repair_time at the ASM level. Because failure group outages are more likely to be transient in nature and because replacing all the disks in a failure group is a much more expensive operation than replacing a single disk, it would … [Read more...] about Oracle ASM 12c – New Features with examples
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Oracle Database 12c New Feature – RMAN “RECOVER TABLE”
Table recovery Table recovery was possible in earlier releases as well. Until previous releases, if we wanted to recover a table, we had the following options: Database point in time recovery (DBPITR) Tablespace point in time recovery (TSPITR) Flashback technology The RECOVER TABLE command is a new feature in 12C that allows a point in time recovery of a table or a table partition. The table is recovered into an auxiliary instance and there is the option to: import the recovered … [Read more...] about Oracle Database 12c New Feature – RMAN “RECOVER TABLE”
Interview Questions : Oracle Flex ASM 12c
What is Oracle Flex ASM? Oracle Flex ASM is an ASM instance which will be running in the cluster based on cardinality defined. The default cardinality is three, but you can change it using srvctl modify asm command. It means that ASM is not required to run on each node in the cluster. In the previous release, ASM will be running on each node in the cluster and ASM clients (Database, ACFS, ADVM) can only access ASM by using an ASM on the same host. With Oracle Flex ASM, the clients can … [Read more...] about Interview Questions : Oracle Flex ASM 12c
Oracle sql script to report the list of files stored in ASM and CURRENTLY NOT OPENED
Purpose One of the features of ASM is databases consolidation. A single diskgroup will be the repository for multiple databases. The result, having a large number of datafiles. If the files were created using OMF (Oracle Managed Files) format, when the datafile is deleted on the database side, it is also deleted on the ASM side. There may be situations when the datafiles are not deleted on the ASM side, particularly when not using OMF format. With large diskgroups holding large number of … [Read more...] about Oracle sql script to report the list of files stored in ASM and CURRENTLY NOT OPENED
How to move ASM spfile from External Redundancy To Normal Redundancy in version 12.1.0.2 and above
The Ask While Installing the 12c Grid Infrastructure (GI) with the intention of having 3 copies of voting disks and OCR files, we created +GRID diskgroup with 3 underlying luns. However, because we chose "external redundancy" for the diskgroup ended up having just one copy of voting disk and OCR files with no option of multiplexing them in the same group. The Solution Before we get into the solution to this ask, lets first see what exactly is "external", "normal" and "high" … [Read more...] about How to move ASM spfile from External Redundancy To Normal Redundancy in version 12.1.0.2 and above
How To Disable Advanced Analytics in Oracle Database 12c?
The Ask The Advanced Analytics is eanbled on the oracle database 12c as shown below. SQL> select * from v$option where PARAMETER like '%Advanced Analytics%'; PARAMETER VALUE CON_ID ---------------------------------------- -------------------- ---------- Advanced Analytics TRUE 0 User wants to disable this option from database. The Solution In Oracle 12c, Oracle Advanced Analytics is a combination of … [Read more...] about How To Disable Advanced Analytics in Oracle Database 12c?
What is OCFS or OCFS2
1. What is OCFS for Linux? OCFS is an open source clustered file system for Linux designed for use with Oracle RAC on Linux to store Oracle datafiles, redo logs, archive logs, voting disks, quorum files and control files. It is NOT a general purpose file system and should not be used to store a shared Oracle home. OCFS, also referred to as OCFS (Release 1), works with the 2.4 version and later of the Linux Kernel like RHEL, CentOS, SUSE. 2. What is OCFS2 for Linux? OCFS2 is the next … [Read more...] about What is OCFS or OCFS2
Script/Queries to Monitor Temporary Tablespace Usage in Oracle Database
The temporary (sort) segment of a given temporary tablespace is created at the time of the first sort operation, which has to write to disk to free up sort space in memory. The first disk sort (after instance startup) creates a sort segment in the temporary tablespace. Multiple transactions which need a sort on disk can share the same sort segment, however, they cannot share the same extent. The sort segment expands by allocating new extents. The sort extents are not de-allocated while the … [Read more...] about Script/Queries to Monitor Temporary Tablespace Usage in Oracle Database
How to monitor Undo Tablespace Usage and the Free Space in Oracle Database
This post provides the various queries that can be used to monitor Undo space usage. The Undo Space once allocated won't be deallocated to the OS, by default. But the space can be reused by other transactions once the UNDO_RETENION (or TUNED_UNDORETENTION period) is met. 1. To check the current size of the Undo tablespace: select sum(a.bytes) as undo_size from v$datafile a, v$tablespace b, dba_tablespaces c where c.contents = 'UNDO' and c.status = 'ONLINE' and b.name = c.tablespace_name and … [Read more...] about How to monitor Undo Tablespace Usage and the Free Space in Oracle Database
Script To Get Tablespace Utilization In Oracle Database 12c
This is a script to get the tablespace utilization in Oracle Database 12c. You can use this script to get the tablespace utilization ALLOCATED(MB), USED(MB) and Used parentage for all containers tablespaces. sqlplus -s / as sysdba set pages 80 set lin 120 set echo off set feed off column PCT format 999.99 column tbspce format A30 col container for a30 select substr(f.tablespace_name,1,30) tbspce, round(f.tsbytes/(1024*1024),0) "ALLOCATED(MB)", … [Read more...] about Script To Get Tablespace Utilization In Oracle Database 12c