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Replication and the ROWID

2 posts in Replication Last posting was on 2003-10-31 21:52:56.0Z
Mark Petryk Posted on 2003-10-31 17:34:31.0Z
Message-ID: <3FA29D27.7040504@lorimarksolutions>
Date: Fri, 31 Oct 2003 11:34:31 -0600
From: Mark Petryk <mark@lorimarksolutions>
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CC: "Mike Petryk" <mike@petryk.net>
Subject: Replication and the ROWID
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from the help file: "Advantage supports the ROWID pseudocolumn in SQL
statements...End users and application developers can use rowids for
several important functions: Rowids are unique identifiers for rows in a
given table"

The rowid field does not contain any information about the client
database that the row was created on. The field only resolves down to
the 'database' + 'table' + 'record number'.

I would like to use this field as a record identifier within my
database, without having to create and manage my own guid field, but
this field has to be unique even across replicated databaseies. I can't
tell from the help file if this rowid field will work for that.

In a synchronized database, is it not possible for two records to be
added, each on a seperate synced copy of the database, to receive the
same 'record number' and therefore have a conflict on this rowid field?
If this field can use used as a unique identifier for rows in a given
table, how are potential conflicts handled in a replicated database
scenario?

Thanks, in advance, for the help.


Brad Schmidt Posted on 2003-10-31 21:52:56.0Z
From: Brad Schmidt <brad.schmidt.nospam@extendedsystems.com>
Newsgroups: Advantage.Replication
Subject: Re: Replication and the ROWID
Date: Fri, 31 Oct 2003 14:52:56 -0700
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Mark,

I'm not positive, but I think the unique identifier for replication
needs to be a physical column(s) in the table. I don't think ROWID can
be used as I don't think it is persistent (in that you are guaranteed to
have the same ROWID generated each time the SQL stmt would be run)

In article <3FA29D27.7040504@lorimarksolutions>, mark@lorimarksolutions
says...

> from the help file: "Advantage supports the ROWID pseudocolumn in SQL
> statements...End users and application developers can use rowids for
> several important functions: Rowids are unique identifiers for rows in a
> given table"
>
> The rowid field does not contain any information about the client
> database that the row was created on. The field only resolves down to
> the 'database' + 'table' + 'record number'.
>
> I would like to use this field as a record identifier within my
> database, without having to create and manage my own guid field, but
> this field has to be unique even across replicated databaseies. I can't
> tell from the help file if this rowid field will work for that.
>
> In a synchronized database, is it not possible for two records to be
> added, each on a seperate synced copy of the database, to receive the
> same 'record number' and therefore have a conflict on this rowid field?
> If this field can use used as a unique identifier for rows in a given
> table, how are potential conflicts handled in a replicated database
> scenario?
>
> Thanks, in advance, for the help.
>
>

Brad
--
* Brad Schmidt
* Extended Systems, Inc