DEPICT: DiscovEring Patterns and InteraCTions in databases A tool for testing data-intensive systems

Problem context (1) Modern enterprise class systems are heavily based on RDBMS (Relational DataBase Management System). Each one of those systems can have its own subsystem for enforcing the consistency and the integrity of the data. Mainly they are in the form of: – Business Logic Layer (often built on top of a middleware) – Business Rules (declarative approach) – Constraints and procedures at the RDBMS level – Any combination of the previous ones No matter how those subsystems are implemented, their role is vital to the whole system. DEPICT - DiscovEring Patterns and InteraCTions in databases 2

Problem context (2) So a crucial question, in a testing environment, is: «How can we reliably verify the coverage of a test suite?» The wide variety and complexity of those subsystems makes really hard to devise a common test strategy Since we are mainly interested in the integrity of the data why not directly involving it in the test process? DEPICT - DiscovEring Patterns and InteraCTions in databases 3

The idea behind We propose the use of classification tree models: they are simple and intuitive. They are effective because they: – Present a high-level view – Are Visual In DEPICT a classification tree models a «Data Interaction». A «Data Interaction» is a set of values coming from different fields in different tables of a database schema. DEPICT - DiscovEring Patterns and InteraCTions in databases 4

The overall process DEPICT - DiscovEring Patterns and InteraCTions in databases Import data interaction model as well as test cases into DEPICT Specify a data interaction Run checks and analyze the results Create or import test cases from an external repository

An overview of the tool (1) DEPICT - DiscovEring Patterns and InteraCTions in databases DEPICT is realized as an Eclipse RCP (Rich Client Platform) Application. It makes use of CTE-XL (Berner & Mattner Systemtechnik GmbH) for classification tree modelling and test cases management. Developed in collaboration with the Directorate of Norwegian Customs and Excise, Oslo, Norway 6

DEPICT features DEPICT - DiscovEring Patterns and InteraCTions in databases 7 Different DBs Located anywhere

An overview of the tool (2) DEPICT - DiscovEring Patterns and InteraCTions in databases Navigator view for browsing the workspace across projects and imported model Interaction Coverage graphs E-R Model Graph of the imported data interaction Interaction Coverage table 8 Dynamic filtering over data interactions

An overview of the tool (3) Let’s examine the tool through an industrial case study from Norwegian Customs and Excise (NCE) with this concrete use case: «Do our test cases cover alcohol importation test requirement?» DEPICT - DiscovEring Patterns and InteraCTions in databases 9

Step 1: Data Interaction model DEPICT - DiscovEring Patterns and InteraCTions in databases By the means of CTE XL we create the classification tree. The first two levels of the tree represent the catalog and the schema (optional) names (useful for accessing the database metadata). Third level: DB table names. Fourth level: Table column names Last level: actual values of the columns relevant to the data interaction. The model defines data interactions relative to the importation of four specific alcohols and two specific categories of declaration. Selected categories: MA: Manual inspection FU: Processed declarations Selected categories: MA: Manual inspection FU: Processed declarations Test focuses on: Whisky, Vodka, Rum, Beer Test focuses on: Whisky, Vodka, Rum, Beer 10

Step 2: Test cases definition DEPICT - DiscovEring Patterns and InteraCTions in databases Below the model the test engineer can create the set of test cases related to the data interaction by simply clicking on the values intersection. In the picture we see an example of 4 test cases related to alcohols whose importation has been manually inspected. 11

Step 3: Import model and test cases (1) DEPICT - DiscovEring Patterns and InteraCTions in databases Importing a CTE-XL model by following the instructions of a wizard procedure. DEPICT will guide the user in the creation of the needed information for establishing a connection toward the DB server. DEPICT can manage practically any DB server provided that a JDBC driver for that server exists. Current version has been tested with: Sybase, MySQL and PostgreSQL. You can have multiple DB connections within the same workspace and/or project. 12

Step 3: Import model and test cases (2) DEPICT - DiscovEring Patterns and InteraCTions in databases During the import procedure DEPICT will: – Validate the CTE-XL model against the DB metadata. – Translate the classification tree in a graph according to the E-R (Entity-Relationship) model in order to obtain a set of feasible and effective SQL statements. – Make a copy of the model within its workspace. 13

Step 4: Run tests and analyze results (1) DEPICT - DiscovEring Patterns and InteraCTions in databases This is the navigator view in which the user can browse the workspace across multiple projects and models. A click on a model will trigger an update of all the views 14

Step 4: Run tests and analyze results (2) DEPICT - DiscovEring Patterns and InteraCTions in databases Interaction coverage view Filter to highlight holes in data Expression used for probing the data interaction coverage. 15

Step 4: Run tests and analyze results (3) DEPICT - DiscovEring Patterns and InteraCTions in databases Selecting the filter «Holes in data» we obtain the list of test cases not covered by the current data set which answers to our initial question. 16 Here we see, for example, that the test cases: «Manual inspection» of «Rum» and «Processed inspection» of Vodka haven’t been covered.

Step 4: Run tests and analyze results (5) DEPICT - DiscovEring Patterns and InteraCTions in databases 17

Further use case scenarios DEPICT - DiscovEring Patterns and InteraCTions in databases By the means of DEPICT they: – Can create a DEPICT model, for each «Mask Control», verifying if related test cases have been covered. – Easily organize DEPICT models as a library of models ready to be used – Mantain a traceability from rules to tests – Document tests outcome – Check test cases coverage as new live data arrives 18

Main features DEPICT - DiscovEring Patterns and InteraCTions in databases Full Eclipse integration Graphical editor for classification tree and test cases Management of multiple data sources Display test case coverage in tabular and graphical way Automatically creates complex SQL queries out of simple classification trees 19

Future works DEPICT - DiscovEring Patterns and InteraCTions in databases Model comparison: look for differences between DBs (useful for example for regression testing) Managing multiple relationships between a pair of tables Improving the expressiveness of the model through the use of a Domain Specific Language (DSL): numerical values ranges, enumerated values,... Scheduled execution for time consuming tests that could run overnight. 20