Effectively Validate Query/Report: Strategy and Tool

Steven LuoSr. System Analyst

Barnes & Noble

Session id: 36993

Agenda PART I: Introduction

– Why, when, and how to validate PART II: Strategy

– Basic strategy– Advanced strategy

PART III: Tool– Test script– Engine - sqlUnit

PART IV: Conclusion

Why to Validate?

Assure Data Accuracy– Managers need accurate data to make strategic

decisions– A company’s sales team needs accurate data to

launch market campaign Assure ETL (Extraction, Transformation, and

Loading) Process Correctness– ETL tools– SQL scripts

When to Validate?

Any of the following types of testing needs validation:

– Unit testing– Integration testing– System testing– Acceptance testing– Maintenance & regression testing

How to Validate?

Validation

Automation Manual

Black Box White Box Black Box White Box

Basic Strategy

Advanced Strategy

Basic Strategy

Advanced Strategy

Agenda PART I: Introduction

– Why, when, and how to validate?

PART II : Strategy– Basic strategy– Advanced strategy

PART III: Tool– Test script– Engine - sqlUnit

PART IV: Conclusion

Validating Report/Query

A Query or Report is actually a result set, so validating needs to answer two questions:

Are you getting the result set right?– right data in each cell

Are you getting the right result set? – exact number of records

A Typical Process of Generating Reports

flat files

staging tables materialized view

T0 T1 Tn

ETL steps

report

Stored procedure

…...

Basic Strategy

Assert that each (cell) in the result set matches the data in the source table

– Number– String– Date– Result Set, etc.

Sampling should be used if a result set is big Assert the right number of records in the result set Check duplicated…

Advanced Strategy Try to uncover invalid data item

– Boundary Validation Count, sum, max, min, x not in table,

“between..and” on whole resultset or certain partitions.

– Special Value (constraints) Validation isXXX() and notXXX() e.g. IsNull, notNull, notNegative, notZero

– Business Rule Validation dept1.sale> dept2.sale

Agenda PART I: Introduction

– Why, when, and how to validate ? PART II : Strategy

– Basic Strategy– Advanced Strategy

PART III: Tool– Test Script– Engine - sqlUnit

PART IV: Conclusion

Why Use a Validation Tool?

Automate the validating process– Reduces the cost, time and effort

Reuse the procedures– Write once, run many times on QA box and/or

production box.

Re-factor SQL

Share by group (save to PVCS)

Tool

Open Source – jUnit, etc.– Steven Feuerstein’s utPL/SQL

My tool -- sqlUnit

sqlUnit Overview The framework consists of two major parts

– test scripts– test engine

implemented in java stored procedure with PL/SQL interface

Implement 2 types of strategy– basic strategy– advanced strategy

Record the validating results Monitor long-running validation process

sqlUnit Overview (2)

From the Engine Perspective– run all your test cases defined in your PL/SQL

package From the User Perspective

– write all test scripts – start the Engine

Architecture

Testscripts

Engine

Assert

util

Database

……

Test Script (1)

Write Test script in PL/SQL Define test package Call APIs Define test procedures

– Test procedure MUST begin with ‘test’ – Setup() : – Teardown(): clean up

Test Script (2) Use your business knowledge to get expected

data and actual data – Get raw or original data from source table

such as POS, Daily Sales, etc.– Get data from a report

call API fetchCursorData(…), or using cursor directly, e.g.

cc := my_test_pkg.get_ref_cursor('SCOTT');loop fetch cc into value1,value2,..., valuek; exit when cc%notfound ; if(...) then sqlunit.assert(‘desc’, value1, 100); end if; end loop;

APIs for Basic Strategyprocedure runTestCases(testPackageName varchar2)procedure assert(description varchar2, num1 number, num2 number)procedure assert(description varchar2, str1 varchar2, str2 varchar2)procedure assert(description varchar2, a1 STRING_ARRAY, a2 STRING_ARRAY)procedure assert(description STRING_ARRAY, a1 STRING_ARRAY, a2 STRING_ARRAY)procedure assertQuery(description varchar2, query1 varchar2, query2 varchar2) procedure fetchRefCursorInto(pname in varchar2, parameters in STRING_ARRAY, fetchfields in out STRING_ARRAY, uniqField in varchar2, uniqValue in varchar2 ) function getCountForQuery(sqlstr varchar2) return numberfunction getCountForProcedure(sqlstr varchar2) return number

Test Script Template

Apply Basic Strategy A tool should pick up:

– m column(s) in a row of a result set m: between 1 and number of columns

– m column(s) in n rows of a result set m: between 1 and number of columns n: between 2 and number of rows

Cells to be validated:– cells: between 1 and m*n

Apply Advanced Strategy

Advanced Strategy– Boundary Object– Special value (Constraint)Object– Business Rule Object

Test Script for Advance Strategyprocedure test_adv_1 is obj sqlunitBoundary := sqlunitBoundary(NULL,NULL,NULL,NULL); begin obj.setTestingQuery('my_test_pkg.get_ref_cursor(''SCOTT'')'); obj.setCountCriteria(2); obj.setQueryCriteria('c1 is not null'); obj.setQueryType(1); //1 : store procedure. 0: sql query obj.checkBoundary;

exception when others then dbms_output.put_line('exception! '); end test_adv_1;

Example for Validating Two Queries

How Engine Works

Users start the Engine by calling … exec sqlunit.runtestcases('VALIDATEPACKAGE'); Engine calls back test scripts by calling the

following: set_up; test_1; tear_down; set_up; test_2; tear_down; ... set_up; test_n; tear_down; Test scripts call Framework APIs ….

sqlunit.assert(...) sqlunit.assert(...) sqlunit.assert(...)

Sequence Diagram

testPackage sqlUnit/engine

Runtestcases()

setup

test_1

tear_down

assert

DB

setup

test_2

assert

tear_down

recordResult

recordResult

View results

Actor

Record the Test Result

Use package name as testing result table name.

Monitoring Validation Process

At Engine level, by instrumentation DBMS_APPLICATION_INFO into Engine, you can monitor the progress

At test script, you can instrument DBMS_APPLICATION_INFO to test scripts too.

Get the progress information from v$session_longop in other session

Test Scripts Guideline

Be simple Don’t use the same sql that generates the

report Use Business/domain knowledge

Conclusion

Data accuracy is very important Use automated validating tool whenever

possible

Limitation of validation

“ Program testing can be used to show the presence of bugs, but never to show their absence”

--E. W. Dijkstra

References

Asimkumar Munshi, Testing a Data Warehouse Application white paper http://www.wipro.com/insights/testingaDWApplication.htm

B. Hailpern and P. Santhanam Software debugging, testing, and verification IBM System Journal Vol. 41, No. 1, 2002

Thomas Kyte, Expert One on One Oracle, Wrox, 2001

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