Monday, July 30, 2012

Start Extract to Re-positioning / How to start extract to point-in-time.

we mostly add extract as below

add extract finance ,tranlog begin now

This will make extract to start when you added extract.So the transactions which commited before we added extract will not capture.


Add the Extract group by issuing the ADD EXTRACT command with a timestamp as the
BEGIN option, or by using ADD EXTRACT with the SEQNO and RBA options. It is best to give
Extract a known start point at which to begin extracting data, rather than by using the
NOW argument.


ADD EXTRACT finance, TRANLOG, BEGIN 2011-01-01 12:00:00.000000

If data that Extract needs during processing was not retained, either in online or archived
logs, one of the following corrective actions might be required:
? Alter Extract to capture from a later point in time for which log data is available (and
accept possible data loss on the target).


ALTER EXTRACT
[,ADD EXTRACT {PARAMETERS} 
[, UPGRADE INTEGRATED TRANLOG]
[, DOWNGRADE INTEGRATED TRANLOG]
[, THREAD ]
[, ETROLLOVER]

ALTER EXTRACT finance, TRANLOG, BEGIN 2011-01-01 12:00:00.000000


If you has to start EXTRACT at certain RBA , this could be achieved as below. 

ALTER EXTRACT finance,EXTSEQNO <trailfile#>  ,EXTRBA <rba>

You can also ALTER recovery Checkpoint. but this is not wise and Even Oracle does not support.

Alter the ioextseqno and ioextrba of recovery checkpoint back to its original recovery checkpoint position


Below seqno & RBA can be seen by INFO ,detail
In this example,

Alter extract , ioextseqno , ioextrba


To determine the oldest log that Extract might need at any
given point, issue the SEND EXTRACT command with the SHOWTRANS option.

You can also start Replicat  at Point in time using  , where CSN (commit sequence number ) is  SCN (system change number)  for Oracle database.


START REPLICAT
[SKIPTRANSACTION | ATCSN | AFTERCSN ]


if your replicat is abended and you ALTER it with BEGIN NOW, its status will change to STOPPED.



3 comments:

  1. Many thanks for your post! I really needed this to sync my replication. Spent hours looking at pump and replicat processes wondering what was going wrong.

    Great post!

    ReplyDelete
    Replies
    1. I am glad that post helpful to you.. comments like yours keep me motivated...

      Delete
  2. Thanks for your post. Fixed my problem.
    Even metalink didnt give any easy fix to me.

    ReplyDelete