Physical Standby database Vs. Logical Standby database

Question

I have few questions regarding capability of Logical Standby Database against Physical Standby database.
1. How efficient is Logical Standby database in terms of Physical Standby Database?? How both differ from each other and can I use Logical Standby Database for disaster Recovery?? Can It be use for recovering the failed Primary Instance?? If yes how efficient and reliable it is??
2. What are the known bugs and roadblocks for logical standby database on Oracle 10.2.0.1 on Soalris X86-64?
3.As logical standby database not going to replicate each and every schema of Primary database?? how is the change management effects to the logical standby from primary?? I mean there are some parameters and job that we create on primary how can it be transferred over to the logical standby??

Answer 1

1. How efficient is Logical Standby database in terms
of Physical Standby Database?? How both differ from
each other and can I use Logical Standby Database for
disaster Recovery?? Can It be use for recovering the
failed Primary Instance?? If yes how efficient and
reliable it is??I'm not sure what sort of "efficiency" you're talking about here...
Physical standby is just the old, tried and true application of archived logs to recover a database. Very solid, very old school.
Logical standby, on the other hand, is parsing the redo log, extracting logical change records, and applying them to the standby database. This obviously takes a bit more processing effort, it's newer technology, it doesn't have quite the level of support that physical standby does (i.e. certain data types are excluded), etc. You certainly can use it for failover, but it isn't quite as robust as a physical standby. Of course, this is getting better and better all the time and is definitely a focus of Oracle's development efforts.
On the other hand, logical standby systems can do things other than act as a warm standby. They can be open serving reports, for example. You can create additional structures (i.e. new materialized views) to support reporting. A physical standby is pretty much always going to be in managed recovery mode, so it cannot be queried.
2. What are the known bugs and roadblocks for logical
standby database on Oracle 10.2.0.1 on Soalris
X86-64?a) You'll want to do a Metalink search
b) If you're talking about a high-availability solution, why are you looking at a base release of the database? Why wouldn't you apply the latest patchset?
3.As logical standby database not going to replicate
each and every schema of Primary database?? how is
the change management effects to the logical standby
from primary?? I mean there are some parameters and
job that we create on primary how can it be
transferred over to the logical standby??I'm not sure I understand... Changes made to the primary generate redo. Oracle parses that redo, generates a LCR, and sends that to the standby database where that change record gets applied.
Justin