Re: redo and undo

From: David Fitzjarrell <>
Date: Mon, 5 Mar 2012 08:16:21 -0800 (PST)
Message-ID: <>

LlogMiner reports the SQL statements to redo or undo the change; it does not report the amoujnt of redo generated for the operation specified.  You would need to query the data dictionary for such statistics ( The v$mystat view would show the redo stats for your current session; query v$mystat, run the statement then query v$mystat again and take the difference -- you should see what you're expecting to see in terms of redo generation.  A query to do this is:

select, m.value
from v$mystat m join v$statname n on (n.statistic# = m.statistic#) where like 'redo%';

David Fitzjarrell

From: Paul Harrison <> To:
Sent: Monday, March 5, 2012 8:32 AM
Subject: redo and undo

Hi All,

Let's say I run the following command...  insert into cure.thecure (firstname ,lastname) values('oracle','11gr2'); The table has an index on the lastname column...

Using Log Miner, There is redo and undo for the table block.  The book I'm reading said that all 3 types of blocks (undo, table, index) have generated redo to protect them. I'm lost here because I do not see redo for the index block or the undo block. I only see redo and undo for the table block.

Any help is greatly appreciated.

Log Miner info below:

INSERT      insert into "CURE"."THECURE"("FIRSTNAME","LASTNAME") values ('oracle','11gr2');    delete from "CURE"."THECURE" where "FIRSTNAME" 'oracle' and "LASTNAME" = '11gr2' and ROWID = 'AAARlCAAEAAAAIMAAB';

Received on Mon Mar 05 2012 - 10:16:21 CST

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