Problem solve Get help with specific problems with your technologies, process and projects.

How many schemas per application?

We have a legacy system with three applications, each application with its own database. Should we create one schema for each application or one schema for all three?

Hi Brian, I hope you could provide a recommendation to the following.

  • We have a legacy system (three applications, each application has its own database). The databases are relatively small and old data gets purged yearly.
  • We are migrating to Oracle 10g with a Web-based front-end (in-house development).
  • Users in these applications will access one or more of these three applications. Users are organized by sites.
  • There are currently about 360 tables combined in the three databases. Total users may be a few thousand (not sure what the total concurrent users will be).

My thoughts are along these two options:

  1. Create one schema for each application (three schemas).
  2. Create only one schema for all three applications (one schema).

What would you recommend and why? If you recommend option 1, how would you best organize users/roles since users will access one or more of these three applications?

Thanks a bunch in advance.

Personally, I prefer one schema per application. I go away from this rule of thumb if I have more than one application accessing the same exact data. In that case, I don't want to replicate data, so I have the applications share the same schema. Those are the general rules I design by.

I do occasionally have an application access more than one schema. This is not a problem. Simply figure out what object privileges are needed in each schema and then grant those privileges to a role. Then grant that role to the application users.

Dig Deeper on Oracle database performance problems and tuning

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.