1. Introduction

1. Introduction

Welcome to the DBMaker Database Administrator's Reference. DBMaker is a powerful and flexible SQL Database Management System (DBMS) that supports an interactive Structured Query Language (SQL), a Microsoft Open Database Connectivity (ODBC) compatible interface, and Embedded SQL for C (ESQL/C). The unique open architecture and native ODBC interface give you the freedom to build custom applications using a wide variety of programming tools, or query your database using existing ODBC-compliant applications.

DBMaker is easily scalable from personal single-user databases to distributed enterprise-wide databases. Regardless of the configuration you choose for your database, the safety of your critical data is ensured by the advanced security, integrity, and reliability features of DBMaker. Extensive cross-platform support permits you to leverage your existing hardware now, and allows you to expand and upgrade to more powerful hardware as your needs grow.

DBMaker provides excellent multimedia handling capabilities, allowing you to store, search, retrieve, and manipulate all types of multimedia data. Binary Large Objects (BLOBs) allow you to ensure the integrity of your multimedia data by taking full advantage of the advanced security and crash recovery mechanisms included in DBMaker. File Objects (FOs) allow you to manage your multimedia data while maintaining the capability to edit individual files in the source application.

1.1 Who Should Read This Book?

This book is intended for database administrators who are not familiar with either the concepts and principles of the DBMaker DBMS or the syntax and grammar of the DBMaker SQL query language. However, you should have a general working knowledge of computers, and should be comfortable using the operating system you are using to run DBMaker. Information on the operating system is beyond the scope of this book, and you should consult your operating system documentation if you encounter any problems in this area.

1.2 Information In This Book

This book contains general information on the concepts and principles a database administrator should understand when using the DBMaker DBMS, and gives an overview of how to use the DBMaker SQL commands necessary to create, maintain, and optimize a database. To help you understand the information presented more clearly, examples and illustrations are provided where possible.

The implementation of a DBMS can greatly affect the performance of database operations. It requires many decisions to optimize and tune database performance, such as where to store data, how to access data, whether to have an index, and how to protect the data. This manual provides a background to enable you to understand the effects of the choices you make as a database administrator or an application developer. We assume you are familiar with the SQL language, since SQL commands will be used to illustrate most of the functions DBMaker supports.

Most of the concepts, commands, and examples in this book are presented using dmSQL, the command-line tool provided with DBMaker. In a few cases some database administration functions can only be performed using one of the other DBMaker application tools or utilities. For more detailed information on how to use the application tools and utilities provided with DBMaker, refer to the section "Other Sources Of Information".

1.3 Other Sources Of Information

DBMaker provides many other user's guides and reference manuals in addition to this reference. For more detailed information on a particular subject, you should consult one of the books shown below.

For more information on the SQL language implemented by DBMaker, refer to the SQL Command and Function Reference.

For more information on the ESQL/C language implemented by DBMaker, refer to the ESQL/C Programmer's Reference.

For more information on the tools and utilities provided with DBMaker, refer to the dmSQL User's Guide, the DBATool User's Guide, or the Server Manager User's Guide.

For more information on error and warning messages, refer to the Error and Message Reference.

The subjects listed above are the subjects that Database Administrator's may find most useful. Not all of the DBMaker manuals are listed simply because subjects covered by some manuals may be more relevant to end users or application developers than database administrators. For information on subjects not listed above, refer to the complete set of manuals provided with DBMaker.

1.4 Document Conventions

All of the DBMaker product manuals use a standard set of typographic conventions to make reading easier and clearer.

Italics	Italics indicate placeholders for information you must supply, such as user names and table names. The word in italics should not be typed, but should be replaced by the actual name you want to use. Italics also introduce new words, and are occasionally used for emphasis in text.
Boldface	Boldface indicates filenames, database names, table names, column names, and other similar terms.
Computer	Information that is displayed on the screen is presented in this type. This includes lines that the product displays in response to your input, as well as lines you are required to enter.
KEYWORDS	All keywords used by the SQL language appear in uppercase when used in text.
SMALL CAPS	Small capital letters indicate keys on the keyboard. A plus sign (+) between two key names indicates you should hold down the first key while pressing the second. A comma (,) between two key names indicates you should release the first key before pressing the second key.

1.5 Syntax Diagrams

Syntax diagrams show the syntax for all SQL commands. These diagrams provide assistance when you are constructing a statement on the command line, but cannot remember the syntax and all possible options. An example syntax diagram is shown below.

To use the syntax diagram, simply follow the line from start to finish. Any elements of the command that you cannot navigate around are required. Any elements that you can navigate around are optional, but provide additional options or flexibility.

Any words that appear in italics are placeholders for the actual names used in your database. You should substitute the actual names for these placeholders. In the above diagram, you should replace the table_name placeholder with the name of a table in the database. For example, in the tutorial database, you could replace the table_name placeholder with Customers to execute this command on the Customers table.

You should also note the direction of the arrows. Sometimes it is possible to have a list of items in a command, which is shown in the syntax diagram as a circular path. Both column name fields above can include a list of column names, separated by commas, as is indicated by the circular path you can take by following the arrows.