Why Test a Database?
Just as developers are human and prone to errors, database containing mission critical information and lines of codes on which applications are built is also vulnerable to errors and requires regular maintenance and updating from time to time. Organizations use several applications day in and day out that work on database which gets altered depending on the requirements. The best way to ensure the functioning of these applications is to test them on a regular basis for the new features and changes made in the database. This is what Regression Testing is all about.
What is Regression Testing of Database?
Database regression testing refers to performing regression testing of the database for any new changes and updates made in the database to keep its integrity intact even after modifications in it.
Steps to database regression testing:
Step 1: Decide What to Test in Database Regression Testing?
When it comes to performing regression testing of a database, it is never pre-defined as to which part or kind of database gets updated that requires retesting. The updates keep on occurring in various areas of database and testers need to target those updates to get the most out of their efforts. Generally, database testing comprises of following:
- Incoming data values,
- Outgoing data values (generated for raw queries),
- Database elements (tables, procedures)
- Metadata for web applications
- Data load that’s somewhat we call “load testing”
While performing regression testing of database, if you are adopting an approach of either Black-box testing or White-box testing, your contents for testing would be something like this
- Black-box Testing at the Interface
- O/R mappings (including the metadata)
- Incoming data values
- Outgoing data values (from queries, stored functions, views ...)
- Stored Procedures & Functions
- White/Clear-Box Testing Internally Within the Database
- Database Schema (tables, procedures, etc.)
- Triggers
- View Constraints
- View definitions
- Referential integrity (RI) rules
- Default values for a column
- Data invariants involving several columns
Step 2: Decide When to Test Database for Regression Testing?
When you change something in the existing database or application that runs on the database to refactor it or add new functionality, you need to ensure that you have not broken anything. This requires you to perform regression testing to either fix the errors or roll back to the changes made in the database. Hence, database regression testing is generally done after introducing changes in the database to check the behavior of the modified code. It requires hundreds of new tests to retest in order to check and rectify the newly written code as well as integration with other systems or applications.
If you are working in an agile environment, you need to take the Test-First Approach or Test-First Development (TFD). In this approach of regression testing, you need to prepare test codes parallel to development in order to test the business logics implemented in the database as well as forms, data validation rules, referential integrity, etc. in the database which works like a cycle as mentioned below
- Add a Test
- Run Your Tests
- Update the codes or make changes
- Run Your Tests Again
Step 3: Decide How to Perform Regression Testing of Database?
This is the most important question that comes to the testers’ mind while performing regression testing of the database. Regression testing can be performed both in manual and automated manner.
A common practice in agile team is that testers have their own “sandboxes” to work. A sandbox is basically a technical environment that isolates untested codes form production repository.You can opt for either of them depending on the size of the tests and database.
In my opinion, automated regression testing is more beneficial since it allows testers to test and manage a large number of databases without manual intervention. In other words, it allows you to perform other tasks while the testing automation tool continues to do its job in the background and sends the report of bugs if any.
Automated regression testing of database seems more easy and convenient and adds to the testers’ productivity saving a huge amount of time along with imparting following benefits
- Entire database regression testing process gets automated
- Reduces testing efforts by 50 to 75%
- Testing is done parallel to development
- Extensive test coverage can be achieved
There are several software testing tools that takes care of regression testing. These tools help in getting the testing team up with the database regression testing requirements in no time overcoming several challenges they face in manual testing.
