Migrating databases to another machine

Mohd Adnan Kamarudin  wrote:

> I'm new on Ingres.
> 
> I'm currently using Ingres 6.4 and would like to transfer only the 
> tables to another machine.
> How can I do this without loosing any related object and characteristic 
> as I don't want my running application malfunction due to incomplete 
> transfer of data. (Different data will be loaded upon the completion of 
> tables transfer)
> 
> Regards 
> 
> Adnan

Adnan,

You can migrate a database from one machine/platform to another
using "unloaddb -c" (the "-c" option tells Ingres to make an ASCII
copy).  Unloaddb will create 2 scripts, one to unload the data on 
the current machine and another to reload the data on the new 
machine.  The Ingres DBA Guide provides information on this.
Unloaddb will migrate the entire schema (tables, indexes, views,
database procedures, etc.), but you will need to regenerate 
statistics (since they are not portable).

The new Ingres installation will either need to be identical to the
old (same number/name of disk locations, same users, etc.) for
this to just work.  If that is not the case then you will need to
manually change location names and/or user names.  That is
not difficult to do, but it is something that you would want to
plan on doing (rather than just finding out half way through the
process).

These comments assume that the new Ingres installation
will also be Ingres 6.x.  If you are migrating to OpenIngres
then you may encounter problems relating to the new reserve
words.  Again, usually not difficult to fix but something that 
you would want to be prepared for.
 
I am assuming that you will be using Ingres/Net to access
the data after it is migrated (since there was no mention of
moving applications).  You will need to make sure that Net
is correctly configured and tested.  You can also run the
unloaddb over Net.  It will run a little slower but handles 
data converson and can help when there is insufficient
disk space for an unload on the current machine.

When your scripts run have the output go to a log file.
Check the log file for "E_".  Also, count the number of
tables, indexes and views present in II_TABLES (look
at table_type column).  You should also check to see
that database rules and procedures were recreated
(help rule *; help procedure *; are the easiest ways to
do this).  Spending a few hours validating the move
would be a good idea.  Remember to checkpoint the
database when you are finished.

It also helps to have a contingency plan in case you
encounter severe problems (not likely, but there could
be something like having an invalid/expired authorization
string).  Letting the old database hang around for a 
week or so would not be a bad idea (make sure that
Ingres is not running so that people cannot access it).
Also, remember that you will not be able to use any 
of the checkpoints from the old installation against
the new installation.

I hope that this helps.  Please review the DBA Guide
before attempting this.

Chip Nickolett           ChipN@Comp-Soln.com
Comprehensive Consulting Solutions, Inc.   (www.Comp-Soln.com)
Phone:  262-544-9954     Fax:  262-544-1236
Ingres Q & A
Back to William's Home Page
Email William