Browse Library
Sign In Start Free Trial
Close icon Search icon
Account
Browse Library Sign In Start Free Trial

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying IBM DB2 9.7 Advanced Application Developer Cookbook
  • Table Of Contents Toc
IBM DB2 9.7 Advanced Application Developer Cookbook

IBM DB2 9.7 Advanced Application Developer Cookbook

By : Mohankumar Saraswatipura, Sanjay Kumar
4 (6)
Buy this Book
close
close
IBM DB2 9.7 Advanced Application Developer Cookbook

IBM DB2 9.7 Advanced Application Developer Cookbook

4 (6)
By: Mohankumar Saraswatipura, Sanjay Kumar
Buy this Book

Overview of this book

With lots of new features, DB2 9.7 delivers one the best relational database systems in the market. DB2 pureXML optimizes Web 2.0 and SOA applications. DB2 LUW database software offers industry leading performance, scale, and reliability on your choice of platform on various Linux distributions, leading Unix Systems like AIX, HP-UX and Solaris and MS Windows platforms. This DB2 9.7 Advanced Application Developer Cookbook will provide an in-depth quick reference during any application's design and development. This practical cookbook focuses on advanced application development areas that include performance tips and the most useful DB2 features that help in designing high quality applications. This book dives deep into tips and tricks for optimized application performance. With this book you will learn how to use various DB2 features in database applications in an interactive way.
Table of Contents (15 chapters)
close
close
close
IBM DB2 9.7 Advanced Application Developer Cookbook
Icon
IBM DB2 9.7 Advanced Application Developer Cookbook
Credits
Icon
Credits
About the Authors
Icon
About the Authors
About the Reviewers
Icon
About the Reviewers
www.PacktPub.com
Icon
www.PacktPub.com
Preface
Icon
Preface
Lock Free Chapter
1
Application Development Enhancements in DB2 9.7
chevron up
Icon
Application Development Enhancements in DB2 9.7
Icon
Introduction
Icon
Changing column names online using the ALTER TABLE operation
Icon
Using the CREATE OR REPLACE clause while creating objects
Icon
Using the ALTER TABLE operation in a single transaction
Icon
Using the CREATE WITH ERROR support
Icon
Using the soft invalidation and automatic revalidation support
Icon
Using the ALTER COLUMN SET DATA TYPE extended support
Icon
Using the new TRUNCATE statement
Icon
Using AUTONOMOUS transactions
Icon
Using implicit casting during application enablement
Icon
Using the DEFAULT values and NAMED arguments in procedures
2
DB2 Application Techniques
Icon
DB2 Application Techniques
Icon
Introduction
Icon
Granting and revoking instance-level authorities
Icon
Granting and revoking database-level authorities
Icon
Granting and revoking object privileges
Icon
Implementing static SQL in DB2
Icon
Implementing dynamic SQL in DB2
Icon
Creating Declared Global Temporary Tables (DGTTs)
Icon
Using XML in a declared temporary table
Icon
Improving performance by creating indexes on a DGTT
Icon
Creating Created Global Temporary Tables (CGTT)
Icon
Using generated columns in tables
Icon
Creating a savepoint
Icon
Rolling back to a savepoint
Icon
Using savepoints in JDBC
Icon
Using savepoints in SQLJ
Icon
Creating a sequence object
Icon
Modifying a sequence object
Icon
Referencing a sequence object
3
General Application Design
Icon
General Application Design
Icon
Introduction
Icon
Improving concurrency by using a connection concentrator
Icon
Using trusted contexts for improved security
Icon
Using trusted connections in JDBC
Icon
Using trusted connections in PHP
Icon
Securing data by using DB2 encryption
Icon
Improving concurrency by using enhanced optimistic locking
Icon
Working with user-defined types (UDT)
Icon
Working with structured types
4
Procedures, Functions, Triggers, and Modules
Icon
Procedures, Functions, Triggers, and Modules
Icon
Introduction
Icon
Creating a simple stored procedure
Icon
Using dynamic SQL in stored procedures
Icon
Working with result sets in stored procedures
Icon
Using ARRAY objects in stored procedures
Icon
Handling errors in stored procedures
Icon
Designing external stored procedures
Icon
Using PL/SQL exception handling in a procedure
Icon
Working with the message buffer in stored procedures
Icon
Planning and designing triggers
Icon
Using scalar user-defined functions
Icon
Writing external user-defined functions
Icon
Designing external table functions
Icon
Working with modules in DB2
5
Designing Java Applications
Icon
Designing Java Applications
Icon
Introduction
Icon
Creating connection objects in JDBC applications
Icon
Creating connection objects in SQLJ applications
Icon
Manipulating XML Data in Java applications
Icon
Batch processing in JDBC applications
Icon
Batch processing in SQLJ applications
Icon
Working with scrollable result sets
Icon
Handling errors and warnings in JDBC applications
Icon
Developing Java applications for high availability
Icon
Using SSL in Java applications
6
DB2 9.7 Application Enablement
Icon
DB2 9.7 Application Enablement
Icon
Introduction
Icon
First step towards enabling Oracle application to DB2 9.7
Icon
Using ROWNUM and DUAL in DB2 9.7
Icon
Using CUR_COMMIT concurrency control isolation level
Icon
Implementing hierarchical queries for recursion support
Icon
Using PL/SQL ANONYMOUS block statements
Icon
Handling RAISE_APPLICATION_ERROR in DB2 PL/SQL
Icon
Migrating Oracle database objects on to DB2 9.7
Icon
Porting multi-action triggers from Oracle to DB2 9.7
7
Advanced DB2 Application Features and Practices
Icon
Advanced DB2 Application Features and Practices
Icon
Introduction
Icon
Working with OLAP functions
Icon
Using optimizer profiles
Icon
Using explain utilities
Icon
Using section explain information
Icon
Interpreting db2exfmt output
Icon
Application development in partitioned databases
8
Preparing and Monitoring Database Applications
Icon
Preparing and Monitoring Database Applications
Icon
Introduction
Icon
Preparing applications for execution
Icon
Rebinding existing packages
Icon
Customizing application behavior using registry variables
Icon
Monitoring application performance
9
Advanced Performance Tuning Tips
Icon
Advanced Performance Tuning Tips
Icon
Introduction
Icon
Understanding predicates in SQL statements
Icon
Improving INSERT performance
Icon
Writing effective SQL statements

Using the ALTER COLUMN SET DATA TYPE extended support

ALTER COLUMN SET DATA TYPE was present in the earlier versions of DB2 as well, supporting SMALLINT to INTEGER, INTEGER to BIG, REAL to DOUBLE, and BLOB(n) to BLOB(n+m) conversions; data types could not be cast to smaller data types. In DB2 9.7, the ALTER TABLE statement is extended to support all compatible types, from casting to small data types.

In some cases, data may be truncated upon altering the column data type such as DECIMAL to INTEGER. To avoid the data loss issues, DB2 9.7 scans the column data before the change and writes the error messages, such as overflow errors and truncation errors, into the notification log.

The column data type is set to a new data type only if there is no error reported during the column data scan phase.

Getting ready

To perform the ALTER COLUMN SET DATA TYPE action, the user needs to have one of the following authorizations on the object:

  • ALTER privilege
  • CONTROL privilege
  • ALTERIN privilege on the schema
  • DBADM authority

How to do it...

We can do it using ALTER COLUMN SET DATA TYPE as follows:

ALTER TABLE SALES ALTER COLUMN SALES SET DATA TYPE SMALLINT
ALTER TABLE EMPLOYEE ALTER COLUMN COMM SET DATA TYPE INTEGER

The preceding SQL statements try to change the data type from one to another.

How to do it...

The reason for the failure in the case of second ALTER COLUMN statement is because an MQT "ADEFUSR" is referring to the base table EMPLOYEE.

db2 "? SQL0270N"
21

A column cannot be dropped or have its length, data type, security, or nullability altered on a table that is a base table for a materialized query table.

We can change the COLUMN type in the base table as follows:

CREATE TABLE BTABLE (C1 INT, C2 INT);
CREATE VIEW v1 AS SELECT C1, C2 FROM BTABLE;
CREATE VIEW v2 AS SELECT C1, C2 FROM V1;
ALTER TABLE BTABLE ALTER COLUMN C1 SET DATA TYPE SMALLINT;
REORG TABLE BTABLE;
SELECT SUBSTR(OBJECTNAME,1,20) NAME, SQLCODE, SQLSTATE, \
OBJECTTYPE FROM SYSCAT.INVALIDOBJECTS WHERE OBJECTNAME IN ('V1','V2')
SELECT * FROM v2;

How it works...

The ALTER COLUMN SET DATA TYPE statement downcasts the data type INT to SMALLINT, which invalidates the views V1 and V2. Since we have AUTO_REVAL set to DEFERRED, the dependent objects become invalid until used.

How it works...

As soon as we access the dependent objects after altering the column data type, objects become valid and you won't see them in the SYSCAT.INVALIDOBJECTS system catalog table.

How it works...

There's more...

  • Casting of VARCHAR, VARGRAHIC, BLOB, CLOB, and DBCLOB data types to types smaller than the current one will not scan the table for a compatibility check, as this casting is not supported by DB2 9.7
  • In the case of range partitioning tables, the string data type cannot be altered if it's a part of the range partitioning key
  • The identity column cannot be altered in DB2 9.7
  • In the case of the database partitioning feature, if the altering column is a part of the distribution key, then the new data type must meet the following listed conditions:
    • Same data type as the current one
    • Same column length
    • FOR BIT DATA cannot be modified in the case of CHAR and VARCHAR
CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
IBM DB2 9.7 Advanced Application Developer Cookbook
End of Section 1
Next Section
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected
Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful
Order Page Read Now

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon