Re: Migrating Oracle 7.3.3 to Oracle 8.0.4

From: noone_at_nowhere.com >>
should set the parameter COMPRESS=Y or N. We are using the Oracle database as a datawarehouse. I have found that for some tables in Oracle 7.3.3 the initial extent is around 76 MB and next extent is around 70 MB, if I use the option COMPRESS=Y, it results in the initial extent size of around 320 MB for these tables. What is the implication of this parameter? <<<

To which MotoX replied >>
If the database you are moving is well designed and not heavily fragmented, then I suggest use compress=n (I always use this). <<

Migration is a great oppurtunity to re-org your entire database. Our DBA group has used platform migrations more than once to re-define the entire data base. As it is much faster to import without indexes we predefine all our application owners and tables. Then we import the data with indexes=n, ignore=y, and constraints=n. Then we build our indexes from a script. Follow this with a full import with rows=n to get the constraints, packages, and public synonyms. This way you have total control of table and index placement and sizing. Doing the export/import this way can reduce the total time involved for a sizable database from 1/2 to 2/3 (Unix to Unix via pipes).

Anyway, no matter how you do your import I would like to suggest that you consider creating a special rollback segment to support your import. You can force the import to use this segment by taking all others offline.   

Mark Powell -- Oracle 7 Certified DBA
- The only advice that counts is the advice that you follow so follow your own advice - Received on Sat Dec 19 1998 - 16:55:32 CST