Data Guard Modes include the following three:
- Maximum Protection
- Maximum Availability
- Maximum Performance
Physical
Logincal
Snapshot
In the physical standby database, your standby database is identical to the primary database, even at the block level. So the redo from the Primary could be applied directly to Standby.
MRP - Managed Recovery Process applies the redo entries from archived logs (or from 12c redo logs) to Physical Standby
Logical Standby database is different. It is independent database and its DB name is different from Primary Database.
LSP - Logical Standby Process applies the redo records from archived logs (or from 12c redo logs) to Logical Standby. LSP reads redo and convert it to SQL statement. LSP not applies redo, but applies SQL statement eventually.
Because SQL statements applies then the Logical Standby DB can be higher version of database or lower version. That's why we use Logical Standby DB in case of rolling upgrade.
Standby Logical Database is more resource usage consumable. Because we use LogMiner and other BG processes to read redo, to convert redo into SQL, to evaluate SQL statement, to apply SQL statement. We experience little more overhead that with physical stb db, but it is acceptable.
- Maximum Protection
- Maximum Availability
- Maximum Performance
Physical
Logincal
Snapshot
In the physical standby database, your standby database is identical to the primary database, even at the block level. So the redo from the Primary could be applied directly to Standby.
MRP - Managed Recovery Process applies the redo entries from archived logs (or from 12c redo logs) to Physical Standby
Logical Standby database is different. It is independent database and its DB name is different from Primary Database.
LSP - Logical Standby Process applies the redo records from archived logs (or from 12c redo logs) to Logical Standby. LSP reads redo and convert it to SQL statement. LSP not applies redo, but applies SQL statement eventually.
Because SQL statements applies then the Logical Standby DB can be higher version of database or lower version. That's why we use Logical Standby DB in case of rolling upgrade.
Standby Logical Database is more resource usage consumable. Because we use LogMiner and other BG processes to read redo, to convert redo into SQL, to evaluate SQL statement, to apply SQL statement. We experience little more overhead that with physical stb db, but it is acceptable.
