Re: Using LogMiner to capture and replay parallel transactions

From: Maris Elsins <elmaris_at_gmail.com>
Date: Thu, 12 Jun 2014 14:27:27 +0300
Message-ID: <CABQhObu6Yas2WWtE8yT1C4cYfsLxRwxQ2eK=8=YDZBvzidWG8g_at_mail.gmail.com>



Hi,

Probably a crazy idea and probably it can't even work, and I've never tried anything like this, but what if you created a logical standby, and traced the apply processes on it. I think the SQLs should be sorted properly in these trace files.

---
Maris Elsins
_at_MarisElsins <https://twitter.com/MarisElsins>
www.facebook.com/maris.elsins




On Mon, Jun 9, 2014 at 12:54 PM, <Laimutis.Nedzinskas_at_seb.lt> wrote:


> Hi
>
> I have a task to capture a work done by many users in parallel and prepare
> SQL script such that executing the script yields the same database state as
> the work done by users.
>
> I plan to use LogMiner for that task. However I am not sure how to filter
> and order the contents of V$LOGMNR_CONTENTS so that replay yields the same
> results as the original transactions.
>
> In the Oracle documentation I've found the following statements:
>
> 1.
> http://docs.oracle.com/cd/E11882_01/server.112/e22490/logminer.htm#SUTIL1566
>
> LogMiner returns all the rows in SCN order unless you have used the
> COMMITTED_DATA_ONLY option to specify that only committed transactions
> should be retrieved. SCN order is the order normally applied in media
> recovery.
>
> This looks promising but how to deal with rollbacked transactions ? It
> looks a bit complicated.
>
>
> 2.
> http://docs.oracle.com/cd/E11882_01/server.112/e22490/logminer.htm#SUTIL1574
> When you specify the COMMITTED_DATA_ONLY option, LogMiner groups together
> all DML operations that belong to the same transaction. Transactions are
> returned in the order in which they were committed.
>
> I think this is the order of SQL statments that I need. May be someone can
> confirm that my assumption is correct:
>
> replay of COMMITTED_DATA_ONLY ordered by <commit_scn, scn> yields the
> same database state as the original transactions ?
>
>
>
> Thank you in advance,
> Laimis N
>
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Received on Thu Jun 12 2014 - 13:27:27 CEST

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