Re: IMP Question: Can Import be set to overwrite existing user objects?

"Scott Kerr" <scott.alba_at_verizon.net> wrote in message news:u_3f6.5220$5H.972167_at_typhoon2.ba-dsg.net...
> Hi,
> I'm trying to import a database that was exported elsewhere, where the
> database was modified. I want the modified backup (dmp file) to overwrite
> the older database. Do is use ignore=yes in the paramfile?
> Thanks for help,
> Scott Kerr
>

Ignore=Y means "ignore errors due to the fact that the table I'm trying to create already exists, and just get on to the juicy business of a stack load of inserts into that table".

Does that mean the import overwrites the existing database? Nuh. Not really: it will merely insert records into pre-existing tables. It won't get rid of the data that's already there... and that means that, if you've not got proper Primary Keys, for example, you'll have two records for everything. If the structure of the table is different in the dmp file compared with the table in the database, you'll also not see any changes... export won't do DDL changes on a table that already exists.

Which leaves you up a certain creek without a certain propulsional instrument.

The best I can advise is: know what tables you want to import, truncate them in the database first, then run import in table mode with ignore=y.

The thought also springs to mind that you might be better off creating a small, brand new database -just SYSTEM tablespace to start with. Manually create the identical tablespaces found in the source database, then do a full import from the dmp file. That should get the lot back.

Regards
HJR
>
>
Received on Sat Feb 03 2001 - 22:40:54 CST