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DG physical standby

yxes2013 Newbie
Currently Being Moderated

Hi all,

 

11.2.0.1

Aix 6.1

 

What is the use of this monitoring script output?

 

select instance_name from v$instance;

select name, value, datum_time, time_computed from v$dataguard_stats where name in ('apply lag','transport lag');

 

INSTANCE_NAME

----------------

PRODDR

 

 

NAME          VALUE                     DATUM_TIME          TIME_COMPUTED

------------- ------------------------- ------------------- --------------------

transport lag +00 00:00:00              09/26/2013 14:59:34 09/26/2013 15:00:00

apply lag     +00 07:59:57              09/26/2013 14:59:34 09/26/2013 15:00:00

 

 

Thanks,

zxy

  • 1. Re: DG physical standby
    DK2010 Guru
    Currently Being Moderated

    Hi,

     

    Have you checked on Google v$dataguard_stats i found that link and there is detail of all the column which you are using in your Query : V$DATAGUARD_STATS

    so again you have to read the doc.. to know what is happening there.

     

    HTH

  • 2. Re: DG physical standby
    MohaAGOU Explorer
    Currently Being Moderated

    Hi,

     

    Please read the manuals it says :

     

    •   APPLY LAG - Apply lag is a measure of the degree to which the data in a standby database lags behind the data in the primary database, due to delays in propagating and applying redo to the standby database.
    •   TRANSPORT LAG - Transport lag is a measure of the degree to which the transport of redo to the standby database lags behind the generation of redo on the primary database. If there are one or more redo gaps on the standby database, the transport lag is calculated as if no redo has been received after the beginning of the earliest redo gap.
  • 3. Re: DG physical standby
    saurabh Pro
    Currently Being Moderated

    this are all in document

     

    •   APPLY LAG - Apply lag is a measure of the degree to which the data in a standby database lags behind the data in the primary database, due to delays in propagating and applying redo to the standby database.
    •   TRANSPORT LAG - Transport lag is a measure of the degree to which the transport of redo to the standby database lags behind the generation of redo on the primary database. If there are one or more redo gaps on the standby database, the transport lag is calculated as if no redo has been received after the beginning of the earliest redo gap.

     

    your apply lag is so high because you don't use real time apply. After switching log on primary, log is shipped to standby and applied, so apply lag is reset. Until the next log switch, log will not be shipped to standby, also not applied. So the lag will increase until next log switch.

  • 4. Re: DG physical standby
    yxes2013 Newbie
    Currently Being Moderated

    Of course dear

     

    As usual I can not understand what it said.

     

    • APPLY LAG - Amount of time that the application of redo data on the standby database lags behind the primary database.
    • TRANSPORT LAG - How much redo data (in time units) generated by the primary database is not available or applicable on the standby database at the time of computation.

     

    How can we lag 7 hrs? when all the archivelogs are currently updated to the last sequence?

  • 5. Re: DG physical standby
    yxes2013 Newbie
    Currently Being Moderated

    So does it mean I will issue <alter system switch log file> often?

  • 6. Re: DG physical standby
    Fran Guru
    Currently Being Moderated

    @yxes2013

    Oracle 11g For Dummies:Book Information - For Dummies

     

    @MohaAGOU@saurabh@DK2010

    are you seriously think that are you helping this user? search and paste google/document information can't be EVER a help, you only are feeding a lazy user that call himself "Good DBA"....... This forum is for help, not for "serch for me" or "do my job for me".


    STOP PROMOTING THIS BEHAVIOR!!


  • 7. Re: DG physical standby
    JohnWatson Guru
    Currently Being Moderated

    saurabh wrote:

     

    this are all in document

     

    •   APPLY LAG - Apply lag is a measure of the degree to which the data in a standby database lags behind the data in the primary database, due to delays in propagating and applying redo to the standby database.
    •   TRANSPORT LAG - Transport lag is a measure of the degree to which the transport of redo to the standby database lags behind the generation of redo on the primary database. If there are one or more redo gaps on the standby database, the transport lag is calculated as if no redo has been received after the beginning of the earliest redo gap.

     

    your apply lag is so high because you don't use real time apply. After switching log on primary, log is shipped to standby and applied, so apply lag is reset. Until the next log switch, log will not be shipped to standby, also not applied. So the lag will increase until next log switch.

    Wrong. The apply lag is high because the lazy sloth has not started managed recovery.

  • 8. Re: DG physical standby
    saurabh Pro
    Currently Being Moderated

    are you seriously think that are you helping this user? search and paste google/document information can't be EVER a help, you only are feeding a lazy user that call himself "Good DBA"....... This forum is for help, not for "serch for me" or "do my job for me".


    first of all Fran JohnWatson i don't know if he is a GOOD DBA OR not.  According to me anybody in the forum who is asking the question need's to get answer. I know and you mighht be also knowingthat maximun of the question that are asked on this forum are either documented or might be mentioned on someone's blog. But still they are asked by OP. Just because they belive someone in this forum might have faced this and if something is wrong then he might be rectified for it. As for people of experience like you and many other oracle documents are easy to understand but there are people here who might not understand the same. so to understand the same they ask in the forum. 

     

    And last but not the least i am not helping him i am helping myself.

  • 9. Re: DG physical standby
    chris_c Journeyer
    Currently Being Moderated

    Possibly someone has cunningly enabled an apply delay deliberately so that if any logical corruption occurs the standby can be opened read only to recover. (although if it lives in a tree, move around very little, has a low metabolic rate we should at least consider we have a member of the family Bradypodidae on our hands)



  • 10. Re: DG physical standby
    yxes2013 Newbie
    Currently Being Moderated

    Hi Saur,

     

    Keep your cool dear. Just don't mind your detractors. Keep up the good work.

     

    Thank you very much

  • 11. Re: DG physical standby
    Fran Guru
    Currently Being Moderated

    @saurabh

    "give a man a fish and you feed him for a day, teach a man to fish and you feed him for a lifetime"


    you can't understand something if you don't have a previous knowledge. you only question doubts to solve your current problem. You are not helping anyone. To help yourself as DBA, read, try and later question not question, try and read.

  • 12. Re: DG physical standby
    yxes2013 Newbie
    Currently Being Moderated

    Of course I am reading.

     

    And I did read the saying that ...The Best thing in life is FREE!

     

    Why you people just dont mind your own and leave Saur alone

     

    Are you afraid that someday I will be better than you? By asking questions in this forum?

     

    I thank you anyways for all the critics. This is what makes life colorful.

  • 13. Re: DG physical standby
    Aman.... Oracle ACE
    Currently Being Moderated

    saurabh wrote:

     

    are you seriously think that are you helping this user? search and paste google/document information can't be EVER a help, you only are feeding a lazy user that call himself "Good DBA"....... This forum is for help, not for "serch for me" or "do my job for me".


    first of all Fran JohnWatson i don't know if he is a GOOD DBA OR not.  According to me anybody in the forum who is asking the question need's to get answer. I know and you mighht be also knowingthat maximun of the question that are asked on this forum are either documented or might be mentioned on someone's blog. But still they are asked by OP. Just because they belive someone in this forum might have faced this and if something is wrong then he might be rectified for it. As for people of experience like you and many other oracle documents are easy to understand but there are people here who might not understand the same. so to understand the same they ask in the forum.

     

    And last but not the least i am not helping him i am helping myself.

    Absolutely wrong Saurabh! If you are really willing to help, point to the documentation where it is pointed. You are not doing any help by just copying the info from the documentation and that too was wrongly interpreted by you as John has corrected you. We are all here to help only but some times, a better help is to guide and let the person explore things by himself. Just because an answer is asked doesn't mean that an answer has to be provided, do understand it.

     

    Aman....

  • 14. Re: DG physical standby
    Aman.... Oracle ACE
    Currently Being Moderated

    And I did read the saying that ...The Best thing in life is FREE!

    Really? Where did you read that, any link for that please?

    Are you afraid that someday I will be better than you? By asking questions in this forum?

    Please be respectful to those who are trying to help and guide you to become better. You are insulting the volunteers by saying such things for them. Just because you are not getting answer from someone but a suggestion to do some research, doesn't mean that he/she is not willing to help you. And similarly, doesn't mean that if one is giving you the answers by searching them from the online docs is actually doing a constructive help of yours.

     

    Aman....

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