User`s guide

the database engine does not need to continue searching through the index or the table as soon as it
finds an index entry that does not match the requested customer.
The advantage of this highly organized search through a database table according to an index is speed.
Using indexes speeds up data retrieval and report generation, important factors when reporting on large
database files.
23.2 Using SQL and SQL databases
Perhaps the most popular and most powerful database formats are DBMS applications based on the
Structured Query Language (SQL). SQL databases usually work over a client/server network architecture,
providing an SQL Server to create, store, and manipulate database files, tables, fields and records,
and an SQL Client interface allowing workstation users not only to design and work with database files,
but also to retrieve useful and meaningful data that will help them in their everyday work.
23.2.1 What is SQL?
SQL is a query language designed for organizing, managing, developing and querying large relational
databases over computer networks. SQL is a common language in the Information Science (IS) and
Information Management industry. The language has been standardized by the American National
Standards Institute (ANSI) and the International Standards Organization (ISO), meaning that there are
specific features that must be present in any version of SQL produced by a software company in order
for that version to be officially called SQL. Many software vendors add more advanced features to their
version of SQL in an effort to improve the language and attract customers, but it must retain the original
standards established by ANSI and ISO.
SQL is not a true computer language. It cannot be used to create stand-alone computer applications
or operating systems. SQL is often referred to as a sub-language, since it can be used within other
languages or applications. Most importantly, the purpose of the SQL language is specific to working
with relational databases.
The syntax of the SQL language is built on a system of sending SQL statements to the SQL database
server. Each statement is a request to perform a database operation, such as creating a database file,
adding tables and fields to a database, adding records to tables, or retrieving data from databases. The
SQL server analyzes the SQL statement and performs the required operation. For example, if the
statement is a request for data, the server gathers the data and returns it to the client workstation for
the user to view.
2012-03-14507
Understanding Databases