why should we enable Supplemental Logging in streams [message #399109] |
Mon, 20 April 2009 12:45  |
kumar.joy
Messages: 69 Registered: August 2007 Location: morrisville
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Member |
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Good Morning Experts,
i have some question on Supplemental Logging in oracle streams.
i am reading oracle documentation., here is the documentation link
http://download.oracle.com/docs/cd/B19306_01/server.102/b14229/strms_capture.htm#i1007293
document says regarding supplemental logging is
Supplemental logging places additional column data into a redo log whenever an operation is performed. A capture process captures this additional information and places it in LCRs. Supplemental logging is always configured at a source database, regardless of location of the capture process that captures changes to the source database.
i was not able to understand what type of additional data that supplemental logging will place?
what kind of data it will place?
is there any possibility to check supplemental logging data?
if yes, can any one provide any kind of documentation or links to test.
is it Mandatory to add supplemental logging at table level?
what happen if i do not enable supplemental logging at source database?
one more question i have archive log mode.
i am configuring one way replication. i have put my source database in archive log mode. do i need to enable archive log mode in target database too?
could any one help us to understand tricky part of supplemental logging.
Thanks,
Jyothy.
[Updated on: Mon, 20 April 2009 12:47] Report message to a moderator
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Re: why should we enable Supplemental Logging in streams [message #403690 is a reply to message #399109] |
Mon, 18 May 2009 01:55  |
gkrishn
Messages: 506 Registered: December 2005 Location: Putty a dark screen
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Senior Member |
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EMP table (emp_no,emp_name,age)
i added supplemental logging for this table for EMPNO column.
SQL> ALTER TABLE scott.emp ADD SUPPLEMENTAL LOG GROUP log_group_PK_EMP (EMPNO) ALWAYS;
Table altered.
even if you update emp_name alone,it will capture emp_no column as well, to make sure it is updating correct record in the destination database.
Hope this small example help you understand it.
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