Re: One vs many databases

These are a few of my considerations

Don't store applications in one database that don't have anything in common: a. when upgrading both applications must upgrade at the same time b. maintenance for one application (where you really want to close access to the db completely) could imply unnecessary downtime for the other application
c. when the database needs to be restored completely (because one application screwed up the data in a yearly batch or so or block corruptions occur and the db runs in noarchivelog mode) the other applications loose data too.
Not that these circumstances occur a lot but...

Store applications in one database when they share data (replication, database links) or are closely related in a way. a. makes recovery scenarios easier. If in multiple db's an incomplete recovery of one of them implies a restore of other db's too to keep the data consistent between applications.
b. can only be done when all object names in the applications are unique (or: this is a chance to make one copy of that table that both applications share).
c. be sure the have solid authorisation setup and procedures in place to prevent unwanted access to data of other applications in the db.

John Hunter <jthunter_at_nbnet.nospam.nb.ca> schreef in berichtnieuws qufR9.3254$Hs3.402088_at_ursa-nb00s0.nbnet.nb.ca...
| Hi Gang,
|
| I'm looking at submitting a business case to management that will justify
| changing from our current structure of many oracle databases to one big
| database. We currently run many separate databases (financial, sales,
| purchases etc...) all based on functional areas. These are all inhouse
| written systems. My problem with having all these instances is with
trying
| to link data together. We need to have realtime data shared amonst the
| systems. Dblinks are quite slow and although materialized views have lots
| to offer they consume a fair amount of overhead.
|
| Anyway, I've done some web searches looking for the pros and cons of many
| instances vs. one instance and have yet to find a good whitepaper on this
| subject. I did read through the long (70 or so posts) when someone said
they
| were going to install 50 instances on one host, but it didn't really
answer
| the question.
|
| Thanks,
| -John
|
|
|
|
Received on Fri Jan 03 2003 - 13:17:52 CST