question on Data Guard -- transmit redo data

From: Guang Mei <>
Date: Fri, 16 Jan 2009 14:21:04 -0500
Message-ID: <ABCFCAE4B2084275B3B1B3C419183F61_at_endc3891a56a15>

I have an oracle Data Guard setup now (physical standby) on two linux boxes that I use for learning. And I would like to know if the db is using "standby redo logs" or "archived logs" to apply the change .

on Primary DB, I have:

SQL> select dest_id,target,log_sequence,AFFIRM,TRANSMIT_MODE from V$ARCHIVE_DEST;

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

         1 PRIMARY           15 NO  SYNCHRONOUS
         2 STANDBY            0 NO  SYNCHRONOUS
         3 PRIMARY            0 NO  SYNCHRONOUS
         4 PRIMARY            0 NO  SYNCHRONOUS
         5 PRIMARY            0 NO  SYNCHRONOUS
         6 PRIMARY            0 NO  SYNCHRONOUS
         7 PRIMARY            0 NO  SYNCHRONOUS
         8 PRIMARY            0 NO  SYNCHRONOUS
         9 PRIMARY            0 NO  SYNCHRONOUS
        10 PRIMARY            0 NO  SYNCHRONOUS

10 rows selected.

Also from Primary DB's init.ora:

log_archive_dest_2 = 'SERVICE=ES_PROD reopen=60' log_archive_dest_state_2 = ENABLE

Based on the above, can I say the setup is "Maximum Performance" mode (I think so, because Affirm=No)? And log shipping (from Primary to Standby) is "ARCH" (because TRANSMIT_MOD=SYNCHRONOUS) ? I can not find anywhere to tell me that if I do not specify say "LGWR ASYNC", what are the default values for these in "log_archive_dest_2"? I only specify reopen and tnsnames entry here.

Also with these configuration and after I created the same number of "standby redo logs" on standby as the primary "online redo logs", and when I made some db changes, then alter system switch logfile on primary, I can see the archived logs were shipped to the standby, the db changes were also there in db (I opened the standby in read-only mode and can see the new tables I created on primary). But I am not sure if the changes were applied through shipped "archive logs" or through "standby redo logs". Basically I want to know if "Redo Archival Process" is LGWR or ARCH? Thanks.

Guang Mei

-- Received on Fri Jan 16 2009 - 13:21:04 CST

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