Open-Source Components for Informix Dynamic Server 9.x

Description

The fast, easy way to leverage IDS 9.x's full object-relational power!

• Supercharge your next IDS-9.x application!
• "Bladelets": easy DataBlade building blocks for powerful object-relational solutions
• Covers Vtables, temporal data management, hierarchical problems, text manipulation, BLOBs, and much more
• CD-ROM: Open source bladelet code for solving a wide range of business problems

Object-relational databases offer immense power — but many database professionals have failed to use it, because doing so required them to write their own DataBlade extensions. This book presents a breakthrough solution: bladelets. Created by a team of Informix' leading DataBlade experts, bladelets serve as building blocks, bringing Informix Dynamic Server 9.x ORDBMS power to bear on a wide range of business problems, while requiring far less original programming.

All ten bladelets are covered in detail, with open source code provided on CD-ROM. Whether you use them "as is," or as the model for your own DataBlades, they can dramatically improve the performance, value, and time-to-market of your very next database application. Coverage includes:

• Solving hierarchical problems
• Extending SQL to support temporal data management
• Accessing external files through SQL
• Using SQL as a data type
• Overcoming database portability problems
• Manipulating text with regular expressions
• Removing LVARCHAR size limits
• Using BLOBs more effectively
• Managing multiple versions of your data with virtual tables, and much more

The accompanying CD-ROM contains all of the book's code examples — plus a toolbox of open-source DataBlades, complete with source code, designed to quickly solve a wide range of business problems.

Sample Content

Online Sample Chapter

Taking Advantage of Database Extensibility

Table of Contents

Preface.


Acknowledgments.


1. Taking Advantage of Database Extensibility.

Software Extensibility. How Do We Call It? IDS 9.x Object-Relational Features. Usage Examples. A New Approach to Problem Solving. What's Next?

Node and Hierarchies. Node versus Relational Implementation. Hierarchical Problems. Functions Overview. Indexing and SQL Statements. Client Access. Installation. Limitations and Improvements. Node Component Location. Acknowledgments.

Introduction to Temporal Data Management. Shortcomings of SQL-92 and Goals of the Period Bladelet. Overview of Period Bladelet. UDTs in Period Bladelet. UDFs for Temporal Operations. UDA. Statistics and Selectivity. Summary and Conclusions.

RDBMS Characteristics. The VTI Interface. VTI Description. The Flat-File Interface. Creating an Access Method. Creating a Table. Using the Table. Supported Types. Installation. Registration. Removal. Limitations and Improvements. Flat-File Component Location. Acknowledgments. Reference.

Overview of the Exec SQL Bladelet. Drawbacks and Limitations. Implementation Details for Exec SQL Bladelet. Application Example Using Exec SQL Bladelet. Summary and Conclusions.

The Problem That Shapes Solves. Shape Data Types. Functions Overview. Indexing and SQL Statements. Client Access. Installation. Limitations. Shapes Bladelet Location. Acknowledgments.

How Do Nonstandard Features Come About? Why Not Stick to Standards? Solving the Portability Problem. Example 1: Oracle Compatibility. Example 2: IBM Compatibility. Conclusion. Obtaining SqlLib and Iutil. Acknowledgments.

Regular Expressions. Regexp SQL Routines Overview. Built-in SQL Functions Overview. Regexp versus Built-In SQL Functions. Performance. Installation. Limitations and Improvements. Regexp Bladelet Location. Acknowledgments.

The Problem That mrLvarchar Solves. Candidate Data Types. Functions Overview. Inserting Data. Selecting and Searching Data. Extracting Substrings. Modifying Data. System Administration. Indexing and SQL Statement. Client Access. Installation. Limitations. mrLvarchar Bladelet Location. Acknowledgments.

Using BLOBs in Image-Enabled Applications. The JPEG Image Format. The LLD Module. JPGImage Bladelet Features. Using the JPGImage Bladelet. Conclusion. JPGImage Bladelet Locatio. Acknowledgments.

Using VTable. Limitations and Future Enhancements. Where to Get the VTable Distribution. Acknowledgments.

Preface

Preface

When we look at the evolution of programming languages, we quickly notice that the programmer's productivity increases with the level of abstraction of the language. The step from binary code to assembler greatly increased productivity because it took care of translating symbolic addresses and variables to their corresponding memory addresses. Third-generation languages added structures and programming constructs, providing yet another jump in productivity. One of the most underrated features is function prototyping, which was added to some languages when object-oriented languages started gaining momentum. This gave the compiler additional information to check for proper argument types, reducing a number of run-time errors that were often difficult to locate.

The rise of object-oriented programming languages provided a more formal way to encapsulate functionality and divide complex problems into subcomponents. In today's object-oriented languages we also find prepackaged object classes, such as the Java Class Libraries, that provide a solution to common problems that occur frequently in most systems. This frees the programmer from these tasks, increasing productivity.

What has happened on the database side? A lot of progress was made on database administration over the last 20 years. On the programming side, we've seen the creation of stored procedure languages that can run procedural code over Structured Query Language (SQL) statements in the database. This improvement was added to relational databases several years ago. Furthermore, this had little impact on the database system as it consists of adding a procedural programming language closer to the database. This procedure language improves performance by reducing the

overhead of data transfer between the database and the application. Because stored procedures are old news by now, it led industry analysts to declare that databases are now a commodity. Of course, they are commodity products as long as you are willing to program to the lowest common denominator. This means that you use as few features as possible and make your life more difficult. This leads to longer development time and slower performance.

Several years ago, a new database model appeared, the object-relational database. Because this model builds on the relational model, it is its superset. This has the benefit of preserving sizable investments made in relational databases over the last few decades. Some of the benefits of this new model were recognized and a new SQL standard was created to describe it. The relational model is opened up to allow programmers the capability to add new functionality that will make the database better suited to a specific business environment.

The new standard talks about adding new data types and functions in the database server. What do we do with these new features? For some reasons, this new functionality has been understood as something to support multimedia. Nothing could be further from the truth. It is about using the proper business and support types and business functions to arrive at a more optimal solution. A few books discussing the implementation of the object-relational technology tried to address this issue. These books include:

• Object-Relational DBMSs: The Next Great Wave
  Michael Stonebraker with Dorothy Moore
  ASIN: 1-55-860397-2 (out of print)
• Object-Relational DBMSs: Tracking the Next Great Wave
  Michael Stonebraker, Dorothy Moore (contributor), Paul Brown
  ISBN: 1-55-860452-9
• Informix Dynamic Server.2000: Server-Side Programming in C
  Jacques Roy
  ISBN 0-13-013709-X
• Object-Relational Database Development: A Plumber's Guide
  Paul Brown
  ISBN 0-13-019460-3

These books cover multiple examples of application of the new technology, analysis, design, and implementation of your solutions. So, what's missing?

Until now, it appeared that you had two choices:

• Buy a commercial DataBlade module such as the spatial, TimeSeries, and Text DataBlades.
• Write your own extensions from scratch.

There is space for at least one more possibility. Many business applications can use simpler extensions that can be used as components in a larger solution. The Informix team has dubbed these Bladelets. They consist of smaller packages that provide some utility functionality. This is similar to foundation classes in many object-oriented languages. They are building blocks that allow you to build your business systems starting at a higher level of abstraction: You don't need to start by writing the equivalent of your own string class.

This book takes a different approach from its predecessors. Instead of assuming that people want to build their own extensions from scratch, it introduces a set of extensions that can be used as tools to build business solutions. These extensions can be quickly added to a database and used within SQL statements. The development effort is now spent in designing new solutions and writing the appropriate SQL statements. Because people are already familiar with SQL, it requires little effort to review the new "verbs" and data types available. The increase in productivity is almost instantaneous!

This book covers a varied set of Bladelets that cover a wide range of problems. Each chapter introduces one open-source component, or Bladelet. The focus is more on where the component can be used than how to use it. The chapter's corresponding appendix goes into the details of the functionality. With examples on how to use the component, the designer is better equipped to imagine more efficient approaches to solve critical business problems.

This book covers a subset of the Bladelets available. The descriptions provided will hopefully help you figure out better ways to solve your business problems. Other Bladelets can be useful to you. They are available in the Informix Developers' Network Web site, under the DataBlade developer's corner. The Web site address is:

www.informix.com/idn

This is also where you can find up-to-date code for the Bladelets described in this book. The two locations to look at are:

www.informix.com/idn-secure/DataBlade/Library/downloads.htmwww.informix.com/idn-secure/foundation/WebPages/bladelets.htm

You can also send questions and comments to the people maintaining this site using the following email address: idn-datablades @informix.com. You can also make suggestions for new Bladelets.

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