In my previous post Part-2 i only highlighted the most useful features but in this post i will target all other new features which brings in significant difference to this release.
1. Architecture
1.1 Read/Write and Read-Only Instances
Starting with Oracle 12.2.0.1 , a new initialization parameter has been introduced which can open the database in Read Only Mode. In past only standby databases were capable of doing so but with 12cR2 DBA can set the INSTANCE_MODE initialization parameter to
READ_ONLY, Default being READ_WRITE.1.2 Process Monitor Process (PMON) Group
The PMON group includes PMON, Cleanup Main Process (CLMN), and Cleanup Helper Processes (CLnn). These processes are responsible for the monitoring and cleanup of other processes.
2. Maximizing Availability
2.1 Restore Point :
Restore points can now be created in PDB's called PDB Restore Points. These restore points are specific to PDB's.
2.2 Flashback Database
As like Restore point PDB's , now a DBA can rewind the database at PDB level to previous point in time without impacting CDB or other PDB's.
2.3 Sparse Backups
This is a most interesting feature to support Oracle Clone DB also know as Snapshot databases and compete Delphix Technology. Oracle has played smart by adding this feature called Sparse Backups.
You must be wondering what's Sparse Backup , its nothing but taking level 1 backup on Clone/Snapshot DB i.e. backing up only changed data.
To know more about Clone DB which works on copy on write technology read Oracle Documentation. There is also a whitepaper which gives more insights about the same.
Unlike the base database, sparse databases are read-write databases.
RMAN restores sparse data files from sparse backups and then recovers them from archive and redo logs. You can perform a complete or a point-in-time recovery on sparse data files.
2.4 Oracle 12c GoldenGate Database Enhancement
In Oracle 12cR2 Oracle have added significant enhancement to GG that enhances its replication capabilities. Couple of them i liked the most are:
- A new view GG_LAG is introduced to view end to end Lag information.
- Automated remote trail file recovery by pump automatically handles when a target system is restored to a previous point in time. This feature also handles most cases where target trail files are deleted or corrupted by automatically regenerating the missing target trail data when the source trail data is available, and by intelligently skipping any duplicate transactions when applying the change data.
For more information please go through Oracle Documentation:
3. Oracle SQL Enhancement
3.1 Join Groups
Join Group is an object that specifies frequently joined columns from the same table or different tables. Such columns typically contain values of compatible data types that fall in similar ranges. When you create a join group it gets created in Oracle In-Memory Column Store which contains special metadata for the columns, which enables the database to optimize join queries for the columns.
Syntax:
CREATE INMEMORY JOIN GROUP Emp_Grp (EMP(dept_id), Dept(dept_id));
4. Other New Features
- There has been introduction to In-Memory column store for Standby Databases.
- DBA's Can now generate AWR reports at PDB Level.
- In SQL Language , Developer can write Query to convert Structure Data into Json format.
- PDB Lockdown Profiles are another good introductions.
- Using In-Memory Column Store with ADO.
- Application Containers, If you have a real use case these Application containers will come real handy when designing the application with multiple depended PDB's accessing common objects.
Summary
This was my last installment to Oracle 12c Release 2 New Feature Topic. I leave rest of the features for you to go through and get more insights on..
In my upcoming blogs i will start Blogging about practical use and use cases of these new features.
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