AW: Replication question

Hi Dennis,

sorry to spoil your MS SQL Server guy's day, but I have to say that some of the mechanisms in SQL Server didn't convince me either. Especially Log Shipping, which we tried to do, but discarded as an option since it is far too "not-working-as-promised" when it comes to certain scenarios like multiple servers in different domains. A lot of Active Directory stuff has to be considered there, too. That's a good way to have multiple-points-of-failure ;). Not what I want when it comes to replication.

Oracle's AQ might be more complicated at first glance, but it also gives you lots of options.
We even got asynchronous master-master repl. running on 8.0.5 (yes, it's ancient) and it works (and it is reliable).

Regards,
Stefan

-----Ursprüngliche Nachricht-----
Von: DENNIS WILLIAMS [mailto:DWILLIAMS_at_LIFETOUCH.COM] Gesendet: Donnerstag, 20. Juni 2002 16:33 An: Multiple recipients of list ORACLE-L Betreff: RE: Replication question

Yechel - Wow, what a blow to be struck with the dreaded RTFM first thing in the morning. Thanks Yechiel, I needed that.

        Actually, I was hoping there was another resource besides the manual, for two reasons:

1. This development group is a little irritated that they are forced to use Oracle instead of MS SQL, so they are taking replication issues as being Oracle limitations.
2. They have been talking to the Quest salespeople, who naturally heap disdain on Oracle's standard replication (selected Oracle SE because the price was closer to MS SQL). I asked the Quest rep if they had a document similar to the Oracle manual. Gosh, he couldn't think of one. Since nobody on the list has mentioned one, maybe they don't have one. The best resource I've found so far is a former Sybase DBA who was able to confirm that log-based replication has most of the same issues as Oracle standard replication has. Thanks everyone for your replies.

Dennis Williams
DBA, 20% OCP
Lifetouch, Inc.
dwilliams_at_lifetouch.com

-----Original Message-----
Sent: Thursday, June 20, 2002 6:29 AM
To: Multiple recipients of list ORACLE-L

Hello Dennis

Well, it is time for me to say: RTFM.
The replication docs have a discussion on conflict resolution, possible conflicts and the ways to resolve them.

Yechiel Adar
Mehish
----- Original Message -----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Sent: Wednesday, June 19, 2002 9:52 PM

> Thanks Yechiel
> My apologies, I didn't make myself clear. I was thinking more along
the
> lines of "if a table can be updated at multiple locations, how do I keep
> those updates from stepping on each other". For example, you could add an
> additional column named "location". Now each site has their own records.
If
> that won't work for some tables, you might add a column "update_time". Now
> you can set a conflict resolution rule that the "last update wins". Maybe
I
> should rephrase my question:
> Is there a list of potential schema changes, with whatever
replication
> tool, that I can show this developer so he can see what work is ahead of
> him?
>
> Also, I was intrigued by your comment that Oracle Advanced Replication
would
> use fewer resources (than standard replication, I assume). I have not
heard
> this before, can you elaborate? Thanks
>
> Dennis Williams
> DBA
> Lifetouch, Inc.
> dwilliams_at_lifetouch.com
>
>
> -----Original Message-----
> Sent: Wednesday, June 19, 2002 11:03 AM
> To: Multiple recipients of list ORACLE-L
>
>
> Hello Dennis
>
> The only schema changes you need for advance replication
> is primary key for each table (not a must but preferable).
>
> Quest product, Shareplex, also prefer primary keys.
> According to Quest (not tested yet) their product use a lot less resources
> on the source system because AR is implemented via triggers.
>
> The use of stand by against AR is the use of the second database.
> If you want to use it for queries or even update you need advance
> replication.
> Also, I think that AR will send a lot less data through the network
> and the same for Quest Shareplex.
>
> Synchronous Vs asynchronous depends on the need for two phase commit
> or you can live with a slight lag. It also depends on the network.
> Also, from the docs, asynchronous use more resources in the source system,
> as it writes the updates to an oracle table, reads them, send them across
> and then delete them from the tables.
>
>
> Yechiel Adar
> Mehish
> ----- Original Message -----
> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> Sent: Friday, June 14, 2002 4:58 PM
>
>
> > We are just starting to look at replication so each manufacturing plant
> can
> > have their own server. The applications are being developed in-house. I
> feel
> > the first issue is to analyze each table and decide how it will be
> > replicated and what schema changes need to me made to accommodate
> > replication. Instead, one of the developers wants to talk to Quest about
> > their solution. It seems to me that you need to make the same evaluation
> and
> > schema changes where needed. If anyone can point me to a white paper on
> > schema changes to consider, that would be appreciated.
> >
> > Dennis Williams
> > DBA, 20% OCP
> > Lifetouch, Inc.
> > dwilliams_at_lifetouch.com
> >
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > --
> > Author: DENNIS WILLIAMS
> > INET: DWILLIAMS_at_LIFETOUCH.COM
> >
> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> > San Diego, California -- Public Internet access / Mailing Lists
> > --------------------------------------------------------------------
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB ORACLE-L
> > (or the name of mailing list you want to be removed from). You may
> > also send the HELP command for other information (like subscribing).
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Yechiel Adar
> INET: adar76_at_inter.net.il
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing Lists
> --------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: DENNIS WILLIAMS
> INET: DWILLIAMS_at_LIFETOUCH.COM
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing Lists
> --------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Yechiel Adar
  INET: adar76_at_inter.net.il

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: DENNIS WILLIAMS
  INET: DWILLIAMS_at_LIFETOUCH.COM

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).


 
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Stefan Jahnke
  INET: Stefan.Jahnke_at_bov.de

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).