Re: Disabling rollback. Is it possible?

milapier_at_ge.hydro.qc.hq (Michel Lapierre) wrote:

>The only reason to use a database in read only it's when you have only
>query to do and no insert, update or delete.
 -snip-
>People have problems with rollbacks because
>the do not know how to manage that object. I suggest you to read
>about How to manage rollback segment.

-snip-

Michel, your comments are quite legitimate in an OLTP environment but if you remember from Chuck's original post, he was referring to a Data Warehouse. Frequently in a Data Warehouse you are dealing with enourmous amounts of information - tables with millions of rows, often involving complex joins. It is crucial that you optimise every operation, including the likes of table loads. Disabling logging is one such technique, the theory being 'I don't care if the operation fails because I can always start again.' Obviously you cannot adopt the same approach in OLTP. Have a look at Oracle V7.2, it includes an option that allows you to disable logging on a table by table basis (I think it goes something like CREATE TABLE...NO RECOVERY). This feature will be particularly useful in the creation of summarised data rollup tables. As an Oracle Data Warehouse developer, I anxiously await the release of V7.2 on my platform - Pyramid DC/OSX. If anyone from Oracle is reading this then please hurry it up, I am waiting to take advantage of all the wonderful improvements for Data Warehouse.     

Andrew Esplan Email: magpie_at_netspace.net.au Work: 61-3-9243-3528 Fax: 61-3-9459-1355 Home: 61-3-9882-3488 Melbourne, Australia Received on Sun Aug 13 1995 - 00:00:00 CEST