On Wed, 27 May 1998 09:16:30 GMT, mainini_at_hotmail.com wrote:
>Hi,
>
>I need to make an export/import of a very large database (for
>reorganization purposes). I've tryed already the procedure (via
>exp/imp tools) a couple of times, but the import fase is taking too
>much time and I can't effort too much downtime.
>Does anyone know how to speed up the import fase?
>Thank you very much...
>
> Marco.
The following suggestions have not been researched, nor have I tried
them but:
- Increase the default temporary tablespace parameters and
sort_area_size values to very high values to speed up index creation.
- If you have sufficient number of cpus, and disks import the export
file using mutltiple imports, specifying a list of tables. You could
likewise to table exports to generate multiple export files, together
with a full export specifying rows = N to ensure you get all non-table
related objects.
- Specify indexes=N and create the indexes manually specifying
no_logging. (assuming version 8?). Also for primay keys.
- Create the tables first with constraints, disable the constraints.
Re-enable the constraints afterwards with the novalidate option.
(Import may do this anyway, I've not checked).
- Use a very large redo logs to avoid checkpoints at log switch.
- Make sure the database is in NOARCHIVELOG mode when the import is
run.
Received on Thu May 28 1998 - 00:00:00 CDT