Re: Migrating from Access to Oracle

On Tue, 06 Jul 1999 11:45:36 -0400, CMG <cmgroup_at_pobox.com> wrote:

Hi,

>Greetings -
>
>Our business is built on Access 2, but time to move to SQL Server, or
>preferrably, Oracle, retaining Access as the front end. We'll upsize to
>Acc97, then migrate to Oracle, if it really works.
>
>Has anyone tried such a migration? What was your experience? Any input

i migrated a project from ACCESS 97 to Oracle 7.3. Doing this by using the migration assistion was a fairly easy task. But: when installing the software at the client, the migration wiz ceased to work. (unclear reason) Therefore, you have to take a look at the assistant-created scripts,too. They are named CTABLE.SQL, CTS.SQL etc. They can be found in the A2OWIZ15 directory.

One problem I ran into is that the migration assistant converted DOUBLE values into the NUMBER (36,2) format wich is seen by the ACCESS frontend as text (!!) and caused some runtime errors of course. But when changing the target datatype for the ACCESS double format to NUMBER(12,2) everything got ok. (ACCESS frontend now sees the backend field as DOUBLE)

Another problem I ran into was the name of the ACCESS MDB file to be migrated. I first tried to migrate a MDB named N07_ORA73 but migration failed with a cryptic error message. Then I renamed it to N07_ORA.MDB and migration went ok. Maybe the reason for this could be that numbers at the end of the target database name are not allowed or the target database name is too long.
Did anyone else ran into this problem, too ?

I also experienced that performance got much much slower (the original ORACLE ODBC drivers are used, the backend machine running oracle has lots of ram and low utilization !)
I was told that using INTERSOLV ODBC-drivers should increase performance should help but I did not check this so far. Does anyone have experience with this configuration ? (ACCESS frontend connected to ORACLE backend using Intersolv ODBC)

When installing almost the same app at a differnet client, I experienced a much better performance. This client has a fiberoptic LAN. Therefore, I think LAN performance has to be considered, too.

>or
>links you can provide would be greatly appreciated. I do have the Oracle
>Migration Tools, but I much rather hear the truth about migration from
>an unbiased source.
>
>Thanks,
>Adam Kahn
Received on Wed Jul 14 1999 - 02:38:01 CDT