Oracle_RAC_12C management and actual combat

Oracle12C official document : download from the official website
: Oracle12C software downloaded from the official website, you can try for free;
high availability: business without interruption, data is not lost, as measured by SLA metrics; for the upgrade and maintenance in the response plan, unplanned fault light scene ;
MAA: maximum dostępność Architecture; that is, high-availability solutions, such as RAC, dataguard, Oracle replication (stream copy, advanced replication), GoldenGate (independent), sharePlex (Dell, independent);
the DB2 high availability solutions: HACMP (now renamed is PowerHA), pureScale (similar oracle rac), DB2 HADR (similar oracle dataguard), CDC (independent software);
Mysql high availability solutions: master-slave replication, gelara, DRBD, OGG; specific implementation: DRBD + heartybeat , MySQL + keepalived; corosync the DRBD + + Peacemaker;
the RAC history: from 9i introduced; 100 can be extended to instances when data from official to expansion of the terms;
the RAC disadvantages: 1. 2. the complex management and maintenance of the disk array a single point, 3. The data reliability can not be guaranteed limited scalability;