Datasheet

21
Chapter 1: Introducing T-SQL and Data Management Systems
The query language of Oracle is known as Procedure Language/Structured Query Language (PL/SQL).
Indeed, many aspects of PL/SQL resemble a C - like procedural programming language. This is evidenced by
syntax such as command - line termination using semicolons. Unlike T - SQL, statements are not actually
executed until an explicit run command is issued (preceded with a single line containing a period.) PL/SQL is
particular about using data types and includes expressions for assigning values to compatible column types.
IBM DB 2
This is really where it all began. Relational databases and the SQL language were first conceptualized
and then implemented in IBM ’ s research department. Although IBM ’ s database products have been
around for a very long time, Oracle (then Relational Software) actually beat them to market. DB2
database professionals perceive the form of SQL used in this product to be purely ANSI SQL and other
dialects such as Microsoft ’ s T - SQL and Oracle ’ s PL - SQL to be more proprietary. Although DB2 has a long
history of running on System 390 mainframes and the AS/400, it is not just a legacy product. IBM has
effectively continued to breathe life into DB2 and it remains a viable database for modern business
solutions. DB2 runs on a variety of operating systems today, including Windows, UNIX, and Linux.
Informix
This product had been a relatively strong force in the client/server database community, but its
popularity waned in the late 1990s. Originally designed for the UNIX platform, Informix is a serious
enterprise database. Popularity slipped over the past few years, as many applications built on Informix
had to be upgraded to contend with year 2000 compatibility issues. Some organizations moving to other
platforms (such as Linux and Windows) have also switched products. The 2001 acquisition of Informix
nudged IBM to the top spot over Oracle as they brought existing Informix customers with them. Today,
Informix runs on Linux and integrates with other IBM products.
Sybase SQLA nywhere
Sybase has deep roots in the client/server database industry and has a strong product offering. At the
enterprise level, Sybase products are deployed on UNIX and Linux platforms and have strong support in
Java programming circles. At the mid - scale level, SQLAnywhere runs on several platforms, including
UNIX, Linux, Mac OS, NetWare, and Windows. Sybase has carved a niche for itself in the industry for
mobile device applications and related databases.
Microsoft Access (Jet)
To be perfectly precise, Access is not really a database platform. Access is a Microsoft Office application
that is built to use the Microsoft Jet database platform. Access and Jet were partially created from the
ground up but also leverage some of the technology gleaned from Microsoft ’ s acquisition of FoxPro. As a
part of Microsoft ’ s Office Suite, Access is a very convenient tool for creating simple business applications.
Although Access SQL is ANSI 92 SQL – compliant, it is quite a bit different from T - SQL. For this reason,
I have made it a point to identify some of the differences between Access and T - SQL throughout the book.
Access has become the non - programmer ’ s application development tool. Many people get started in
database design using Access and then move on to SQL Server as their needs become more sophisticated.
Access is a powerful tool for the right kinds of applications, and some commercial products have actually
been developed using Access. Unfortunately, because Access is designed (and documented) to be an end
user ’ s tool rather than a software developer ’ s tool, many Access databases are often poorly designed and
power users learn through painful trial and error about how not to create database applications.
CH001.indd 21CH001.indd 21 3/26/10 11:35:43 AM3/26/10 11:35:43 AM