When should I use stored procedures?

Question

When should I be using stored procedures instead of just writing the logic directly in my application? I\'d like to reap the benefits of stored procedures, but I\'d also lik

Answer 1

This depends entirely on your environment. The answer to the question really isn't a coding problem, or even an analysis issue, but a business decision.

If your database supports just one application, and is reasonably tightly integrated with it, then it's better, for reasons of flexibility, to place your logic inside your application program. Under these circumstances handling the database simply as a plain data repository using common functionality looses you little and gains flexibility - with vendors, implementation, deployment and much else - and many of the purist arguments that the 'databases are for data' crowd make are demonstratively true.

On the other hand if your are handling a corporate database, which can generally be identified by having multiple access paths into it, then it is highly advisable to screw down the security as far as you can. At the very least all appropriate constraints should enabled, and if possible access to the data should be through views and procedures only. Whining programmers should be ignored in these cases as...

1. With a corporate database the asset is valuable and invalid data or actions can have business-threatening consequences. Your primary concern is safeguarding the business, not how convenient access is for your coders.
2. Such databases are by definition accessed by more than one application. You need to use the abstraction that stored procedures offer so the database can be changed when application A is upgraded and you don't have the resource to upgrade application B.
3. Similarly the encapsulation of business logic in SPs rather than in application code allows changes to such logic to be implemented across the business more easily and reliably than if such logic is embedded in application code. For example if a tax calculation changes it's less work, and more robust, if the calculation has to be changed in one SP than multiple applications. The rule of thumb here is that the business rule should be implemented at the closest point to the data where it is unique - so if you have a specialist application then the logic for that app can be implemented in that app, but logic more widely applicable to the business should be implemented in SPs.

Coders who dive into religious wars over the use or not of SPs generally have worked in only one environment or the other so they extrapolate their limited experience into a cast-iron position - which indeed will be perfectly defensible and correct in the context from which they come but misses the big picture. As always, you should make you decision on the needs of the business/customers/users and not on the which type of coding methodology you prefer.