Skip to main content

Virtual Private Database: Beyond the Basics

Virtual Private Database (VPD), also referred to as row-level security or RLS, is a feature built into the Oracle Database that allows you to set up security policies on tables that restrict which rows a user can see or change based on the policy logic.

One of the nicest things about VPD is that this logic (and the fact that a filter is being applied) is completely invisible to the user. They just see the data relevant to them and none the wiser about all that other data in the data.

Here's a simple example to drive the point home: suppose I am building a health care application and it contains a patients table. The security policy is straightforward:
  • A patient can only see their own information.
  • A doctor can see only the information about their own patients.
  • A clinic administrator can see information only about the patients in their clinic.
In all three cases, the user would sign on to the application and execute this identical query and only their rows would appear.

SELECT * FROM patients

Of course, there are lots of different and very interesting aspects to setting up your policies. Back on March 3, 2020, Praveen Kumar of Wipro shared his thoughts about VPD with 100 developers on PL/SQL Office Hours.

He ran out of time before he could explore some of the more interesting challenges and beyond-the-basics features, so we are bringing him back on May 5th at 11 AM Eastern to complete his thoughts! We hope you'll join us. We encourage you to watch last session's video beforehand to get the most out of the May session.

Our Presenter: Praveen Kumar of Wipro

Parveen Kumar is a Java and Oracle Developer with Wipro, based in the UK. He has over eight years experience focused mainly on developing and designing applications using Oracle Database as a primary database. He aims to keep the business logic inside the database and expose data through PL/SQL APIs.

Parveen has in various projects taken advantage of native support for XML, JSON and Object datatypes, SOAP/REST APIs for Web Programming and security features like VPD/RLS, Oracle Wallet for Web APIs and other features which provide true fine grained access to different types of users.

In the May Office Hours session, Praveen will cover these topics and maybe even some more:
  • Policy Groups and how they work and provide better control
  • Application roles in conjunction with VPD more detail
  • Performance issues and analyzing and fixing them
  • Drawbacks and real-time challenges of working with VPDs 
  • Maintenance of VPD policies
Follow this link to subscribe to my monthly PL/SQL Office Hours program, so that you will receive email reminders for this and future sessions.

You can also view recordings of the dozens of past sessions, including:


Labels:

Comments

Post a Comment

Popular posts from this blog

Quick Guide to User-Defined Types in Oracle PL/SQL

A Twitter follower recently asked for more information on user-defined types in the PL/SQL language, and I figured the best way to answer is to offer up this blog post. PL/SQL is a strongly-typed language . Before you can work with a variable or constant, it must be declared with a type (yes, PL/SQL also supports lots of implicit conversions from one type to another, but still, everything must be declared with a type). PL/SQL offers a wide array of pre-defined data types , both in the language natively (such as VARCHAR2, PLS_INTEGER, BOOLEAN, etc.) and in a variety of supplied packages (e.g., the NUMBER_TABLE collection type in the DBMS_SQL package). Data types in PL/SQL can be scalars, such as strings and numbers, or composite (consisting of one or more scalars), such as record types, collection types and object types. You can't really declare your own "user-defined" scalars, though you can define subtypes  from those scalars, which can be very helpful from the p
24 comments
Read more

The differences between deterministic and result cache features

 EVERY once in a while, a developer gets in touch with a question like this: I am confused about the exact difference between deterministic and result_cache. Do they have different application use cases? I have used deterministic feature in many functions which retrieve data from some lookup tables. Is it essential to replace these 'deterministic' key words with 'result_cache'?  So I thought I'd write a post about the differences between these two features. But first, let's make sure we all understand what it means for a function to be  deterministic. From Wikipedia : In computer science, a deterministic algorithm is an algorithm which, given a particular input, will always produce the same output, with the underlying machine always passing through the same sequence of states.  Another way of putting this is that a deterministic subprogram (procedure or function) has no side-effects. If you pass a certain set of arguments for the parameters, you will always get
14 comments
Read more

How to Pick the Limit for BULK COLLECT

This question rolled into my In Box today: In the case of using the LIMIT clause of BULK COLLECT, how do we decide what value to use for the limit? First I give the quick answer, then I provide support for that answer Quick Answer Start with 100. That's the default (and only) setting for cursor FOR loop optimizations. It offers a sweet spot of improved performance over row-by-row and not-too-much PGA memory consumption. Test to see if that's fast enough (likely will be for many cases). If not, try higher values until you reach the performance level you need - and you are not consuming too much PGA memory.  Don't hard-code the limit value: make it a parameter to your subprogram or a constant in a package specification. Don't put anything in the collection you don't need. [from Giulio Dottorini] Remember: each session that runs this code will use that amount of memory. Background When you use BULK COLLECT, you retrieve more than row with each fetch,
4 comments
Read more