Physical vs Logical standby database

In the Oracle HA guide, it is mentioned that we must take Logical backup "in addition" to Physical backup (not instead of Physical Backup)
If I run have two systems i.e a Primary System and a Logical standby database system , is it not sufficient protection ? If the primary fails, can I not recover the primary system using the nightly backup I take from the Logical Standby Database.
If it is not sufficient protection, what exactly I will lose ?
Assume I take the nightly complete hot backup backup from the Logical Standby Database instead of the Primary System to save CPU cycles of the primary system.
In other words, it is said that "physical standby database provides zero data loss without any allowance for data divergence" -- What exactly is meant here ?

Thanks Werner for the reply.
1. If there is a human error (dropping a table by mistake), it will be applied to the standby database irrespective of whether it is physical standby or Logical standby. I am unable to see any advantage with Logical standby database in this case. Am I missing something here ?
Or are there any other type of user errors where Logical standby provides an advantage ? Can you please name some ?
2. If I backup from the logical database and if I am willing to "restore" (instead of recover) the primary from this backup in case of a primary failure, is it not the same effort ?
3. Can't we set up a Logical Standby with Maximum Protection Mode ?
I am aware physical standby offers a better performance and it has no data type restrictions. I do not care about these two. Also, I am aware of the extra features provided by Logical database.
Overall, I am trying to see whether physical standby database has any "feature" which I will miss with Logical standby database. I tried my best with Oracle documentation, but I could not get a clear answer.
Any help is appreciated.

Similar Messages

  • Difference between physical and logical standby database

    What is the difference between physical and logical standby database?

    Hi,
    Physical Standy where its a read only DB.
    Logs are applied.
    Logical Standy where it can be Read / Write DB and the logs are applied in terms of SQL Statements.
    Thanks & Regards,
    Pavan Kumar N

  • CPU patch procedure with physical and logical standby database in place

    Hello All,
    I've also placed this in the Upgrades forum, but perhaps this is the best place to have put it.
    I'm trying to compile a decent set of steps for applying the CPUOCT2008 patch to our production RAC cluster which has both a logical and physical standby in place. I've read a tonne of documentation, including the CPU readme, DOCID 437276.1 and 278641.1. I''ve also read through the Upgrading Databases in a Data Guard Configuration chapter of Dataguard Concepts and Administration. The last doc mentioned is really for upgrading a full version of Oracle rather than applying a CPU (at least I think that's the case). DocID 437276.1 is rather sparse on details.
    I guess what I'm trying to understand is the proper method for applying the patch with the logical standby in place. The physical standby looks pretty straightforward. After running opatch on it as well, it will basically have all of the changes applied to the primary shipped over and applied as per the normal primary/standby relationship. Will the same be true for the logical (having applied the patch, and then re-enabling SQL apply)? Should I aim to have it work that way? By that I mean start it up and re-enable sql apply and then upgrade the primary. Or, am I to apply the catcpu.sql script to it as well before re-enabling the sql apply? Am I wrong in regards to the physical standby as well i.e. should the catcpu also be applied directly to it?
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    Edited by: chris.baron on Dec 12, 2008 11:38 AM

    Given the fact that your system is far from main-stream I'd recommend opening an SR with Oracle Support Services (metalink) and asking them.
    If you would like to publish a White Paper on your experience after you have successfully completed the project let me know off-line.

  • Streams Replication:Source database Physical or Logical Standby DB

    Can the source database in streams replication be a physical or logical standby database ? If so, is the process of configuring streams the same as a regular database ? Are there any best practices or different configuration if the source is Logical or Physical standby DB ?
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  • Logical standby database to physical standby database

    I already start my logical standby database and I want to return it again to physical standby database. So what should I do?

    >
    The "may be" is because I have tested flashback of a physical standby to before resetlogs, but not a logical standby.
    >
    A physical standby keeps the DBID of the primary - a logical standby does not. That is exactly the problem that restricts the reconversion into physical from logical, and you did not encounter that problem.
    >
    I haven't used "keep identity" but from what I read it relates to "convert to physical" not "flashback database".
    >
    Exactly. And that is what the OP wants to do: convert to physical (from logical).
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    In short: If there is no solution for the changed DBID of the logical standby in order to flashback it into physical as you suggested, then it is not possible .
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    Kind regards
    Uwe
    http://uhesse.wordpress.com

  • Physical Standby database Vs. Logical Standby database

    I have few questions regarding capability of Logical Standby Database against Physical Standby database.
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    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??

    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...
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    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
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    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

  • Will logical standby database be replaced by physical standby database?

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    As far as I know, because of the emergence of Real Time Query, physiacl standby database is easier to work than logical standby database. There are so many restrictions on using logical standby database.
    Will logical standby database be deprecated in the future?
    Message was edited by:
    frank.qian

    Good question - you are right that with the advent of Real Time Query, physical standby databases can provide the 'reporting database' functionality that you used to have to use a logical standby database for.
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  • Can i convert logical standby database to physical standby database

    Dear All,
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    I never needed or tested something like this, but below maybe usefull -
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    But opposite is documented - http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ls.htm#BEIGJCAC
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  • Forward physical standby archivelog files to a logical standby database

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  • How to convert logical standby database to Physical Standby Database

    Hi,
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    Thanks.
    Regards,
    RJ.

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    It's somewhat unlikely you are in that situation, but that is a possibility.
    Indeed the 11g snapshot standby does this sort of thing:
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    jason.
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  • Logical Standby Database in NOARCHIVE Mode

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    hi,
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  • Creating logical standby database

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  • Creation of Logical Standby Database Using RMAN ACTIVE DATABASE COMMAND

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    *.log_archive_dest_3='SERVICE=pc01ls LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES, PRIMARY_ROLE) DB_UNIQUE_NAME=pc01ls'
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    *.log_archive_dest_state_2='ENABLE'
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  • Logical Standby Database and XMLDB

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    >
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    >
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    >
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    Exactly. And that is what the OP wants to do: convert to physical (from logical).
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  • Logical Standby databases

    Hi,
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    Does it mean that we can exclude indexes and constraints as present in primary?
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    Physical standby differs from logical standby:
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    Logical standby tables can be open for SQL queries (read only), and all other standby tables can be open for updates.
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    Installing Physical standbys offers these benefits:
    An identical physical copy of the primary database
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    High Data protection
    Reduction in primary database workload
    Performance Faster
    Installing Logical standbys offer:
    Simultaneous use for reporting, summations and queries
    Efficient use of standby hardware resources
    Reduction in primary database workload
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