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Express
Technology Inc. software is designed for the Microsoft Database Engine
(MSDE) and Microsoft® SQL Server 7, 2000 or 2005. The MSDE will work fine
for most clients. However, if you already have MS SQL Server, our
applications will work with version 7 and higher. ExpressTechnology
Inc. software uses the industry standard Open Database Connectivity (ODBC)
to communicate with the database engine. ODBC drivers are usually
included with your operating system. They are also available free
and can be downloaded from our site.
The
following information about SQL is provided by Microsoft Corporation.
Microsoft® SQL Server™ is designed to be a client/server system.
Client/server systems are constructed so that the database can reside on a
central computer, known as a server, and be shared among several
users. When users want to access the data in SQL Server, they run an
application on their local computer, known as a client, that
connects over a network to the server running SQL Server.
Having
data stored and managed in a central location offers several advantages:
-
Each
data item is stored in a central location where all users can work
with it.
Separate
copies of the item are not stored on each client, which eliminates
problems with users having to ensure they are all working with the
same information.
-
Business
and security rules can be defined one time on the server and enforced
equally among all users.
-
A
relational database server optimizes network traffic by returning only
the data an application needs. For example, if an application working
with a file server needs to display a list of the names of salesmen in
Oregon, it must retrieve the entire employee file. If the application
is working with a relational database server, it sends this command:
SELECT
first_name, last_name
FROM
employees
WHERE
emp_title = 'Sales Representative' AND emp_state = 'OR'
The
relational database only sends back the names of the salesmen in
Oregon, not all of the information about all employees.
-
Hardware
costs can be minimized.
Because
the data is not stored on each client, clients do not have to dedicate
disk space to storing data. The clients also do not need the
processing capacity to manage data locally, and the server does not
need to dedicate processing power to displaying data.
The
server can be configured to optimize the disk I/O capacities needed to
retrieve data, and clients can be configured to optimize the
formatting and display of data retrieved from the server.
The
server can be stored in a relatively secure location and equipped with
devices such as an Uninterruptible Power Supply (UPS) more
economically than fully protecting each client.
-
Maintenance
tasks such as backing up and restoring data are simplified because
they can focus on the central server.
In
large client/server systems, thousands of users may be connected to a SQL
Server at the same time. SQL Server has full protection for these
environments, with safeguards that prevent problems such as having
multiple users trying to update the same piece of data at the same time.
SQL Server also effectively allocates the available resources, such as
memory, network bandwidth, and disk I/O, among the multiple users.
While
SQL Server works very effectively as a server, it can also be used in
applications that need a stand-alone database stored locally on the
client. SQL Server can dynamically configure itself to run efficiently
with the resources available on a client without the need to dedicate a
database administrator to each client.
SQL
Server applications can run on the same computer as SQL Server. The
application connects to SQL Server using Windows Inter-process
Communications components (IPC), such as shared memory, instead of a
network. This lets SQL Server be used on small systems where an
application needs to store its data locally. |
