Understanding Client Requesters

A workstation that needs to access database files is considered a client to the machine running the Pervasive.SQL Server product. A piece of software called a client requester, or requester for short, is required to access database files from a Pervasive.SQL database server. Your application's Pervasive.SQL calls go through the requester, which sends them to the Pervasive.SQL Server for processing and then returns the reply to your application.

Pervasive.SQL supplies requester programs for the following environments: Windows NT/2000/XP, Windows 98/ME, and DOS. The Requesters use the TCP, SPX or NetBIOS protocols to communicate with the server MicroKernel, depending on the type of server you have. Ensure that your workstation has the appropriate network protocol software installed.

Types of Requesters

Pervasive.SQL includes the following types of requesters:

You do not load or unload the Requester explicitly (except for the DOS requester); the system loads the Requester with the first application call to Pervasive.SQL and unloads the Requester when you exit your application.

DOS Requesters

This type of requester is used for applications that run under the DOS operating system. You may install only the DOS requesters if that is all you require. SeeInstalling DOS Requesters .

Trace Requesters

Trace requesters are used for troubleshooting (tracing) client problems at a low level. Generally, you will never need to perform this type of tracing. The low-level tracing is intended for use by trained support staff. Your product vendor or Pervasive Software Support will direct you on how to conduct low-level client tracing, which includes how to use the trace requesters.

Note that the tools provided with Pervasive Software solve most troubleshooting issues. For example, you would run the network connectivity tests in Pervasive System Analyzer to verify network connectivity. Also at your disposal is the Pervasive Knowledge Base (http://support.pervasive.com/eSupport), through which you may search for information about particular client issues.

WIN32 Requesters

This type of requester is used for applications that run under a Windows 32-bit operating system.

Installation

You have two choices for installing the requesters: install all three types or install only the DOS requesters.

A single installation program installs all three types of requesters to a client workstation. In addition, a set of Pervasive.SQL utilities is installed and a set of Pervasive.SQL documentation. By default, the requesters and most of the utilities are installed to C:\PVSW. You may change the location during the installation process. The documentation set, Pervasive System Analyzer (PSA), and some common files are installed to Program Files\Common Files\Pervasive Software Shared.

If you require only the DOS requesters. SeeInstalling DOS Requesters .

Configuration

The configuration of requesters is covered in Chapter 18, Client Network Configuration. If you are a system administrator or value added retailer (VAR) and want to configure a large number of client workstations, read Chapter 17, Distributing the Pervasive Client, before configuring individual workstations.

Existing Configuration Settings

If you have an existing installation of the Pervasive.SQL client software on your computer, nearly all of the client configuration values are automatically migrated to the V8 client configuration during the installation process. There are two exceptions that are not migrated, shown in Table 15-1.

*Table 15-1 Configuration Setting Values not Migrated to V8*
Configuration Setting	Value in V8
Client4Access4Use IDS	Off. Because most customers do not use Pervasive I*net Data Server (IDS), by default this setting is turned off to reduce connection time. If you use IDS, you must turn this setting On.
Server Address Table (SAT), not available in Configuration but stored in Windows Registry	The SAT keeps a record of the computers where database servers have been detected or not detected, to improve connection time. This registry key is reset during the installation and will be re-populated over time as you connect to the servers in your environment.