High Availability

Availability:

1.       Low Availability:                   Some downtime + Data loss               (Incomplete Recovery)

2.       Medium Availability:            Some downtime + No Data loss        (Complete Recovery)

3.       High Availability:                   No Downtime + No Data loss             (Complete Recovery)

Low Availability: 

ICR - Loss of redo log files or current control file.

Medium Availability: 

It is a complete recovery example Data guard

Max. Performance: This is the default mode

Max Availability:   Guarantee data availability by compromising database availability

Max Protection:   Guarantee database availability by compromising data availability

High Availability: Its means No downtime & no data loss

                                 Example RAC (it gives the solution for instance crash)

Data guard: Data Availability

RAC: Instance Availability

MAA à Maximum Availability Architecture = Data guard + RAC