HP 3000 Manuals HP 3000 Manuals
A : Information Access
Information Access is a component of HP NewWave Office. It consists of
Access Server, SQL Access/XL, SQL Access/UX, and Access PC. Information
Access allows PC workstations to access information resident on HP 3000
and HP 9000 computers, depending on which server is used, as well as to
access PC-resident databases.
* Access Server is the HP 3000-based data server running on MPE/V
and MPE/XL.
* SQL Access/XL is the HP 3000-based SQL server running only on
MPE/XL.
* SQL Access/UX is the HP 9000-based SQL server running on HP-UX.
* Access PC is the PC-based software with which users retrieve,
manipulate, and save information, locally or on the HP 3000 or HP
9000.
Access Server
Access Server is an HP 3000-based data server. It receives requests to
retrieve information from various data sources, manipulate that
information, and make it available to PC workstations in the desired
format.
Access Server expects the requests for information to come from PC
software, which provides an interactive user interface, or from its Host
Batch Facility, which issues the requests interactively or from an HP
3000 batch job.
Three of the major components of Access Server are the following:
* The Administrator Utility, which provides a quick, convenient
screen interface for performing all operations involving the data
dictionary.
* The data dictionary, in which you define (1) what data will be
available to users running Access PC, (2) who the users are and
how they are grouped, and (3) what portion of the data each group
of users is permitted to access.
* The Host Batch Facility, which allows Access Server to be run
interactively or from a job file invoked from the PC or the host.
Access PC
Access PC for the HP Vectra PC (which also supports IBM PC/XT/ATs and
PS/2s as well as Compaq 286, 386, and 386S PCs) performs the interactive
user interface function for Access Server.
Access PC is a PC-based software tool that allows the user to retrieve,
manipulate, and save information. The information can be retrieved from
a PC database locally or from various data sources on the HP 3000.
An Access PC user need not be concerned with the mechanics of the data
retrieval. The mechanics are handled through method files, which tell
Access PC how to make the retrieval and what to expect back.
PC users can combine and reformat the data they access. They can also
download the results to their PC or save them on the HP 3000 for later
use.
How They Relate
When Access PC requests information from host data sources, a data
communications path is established between the PC and the HP 3000.
Requests for information are then sent to and interpreted by Access
Server. The information retrieved by Access Server is sent to the PC.
The PC user can then manipulate and save the information.
Access Server retrieves information according to what Access PC requests
and what Access Server permits.
The Database Administrator (DBA) controls which databases and files are
available through Access Server. The DBA can be either the primary DBA,
who controls everything in Access Server, or a secondary DBA, who
controls only a subset of the data available through Access Server.
The DBA provides further security by specifying which portion of that
data each user can see. PC users are not allowed to alter databases but
they can overwrite files.
The DBA defines Access Server's restrictions on what data is accessible
and by whom, by using the Configuration screens in the Administrator
Utility. The definitions are stored in a pair of databases that
constitute the Information Access data dictionary:
* HDPDIC. Contains all the information needed to allow access to
data as relational tables.
* HDPENV. Contains all information related to Information Access
users.
Together, Access PC and Access Server use co-processing. That is, both
systems (the PC and the HP 3000) are used for what each does best. The
PC performs local retrievals and "saves" of information and provides the
interactive user interface. The HP`3000 retrieves and manipulates data
from HP 3000.
This tutorial teaches you about Access Server in terms of IMAGE databases
on the HP 3000.
What is "Remote"?
The term "remote" has different meanings depending on who is using
it--the PC user, the primary DBA, a secondary DBA, or the System Manager.
![[]](../../pic3k/M012040/FFN43c50.gif)
Figure 1-1. Perspectives on Access PC and Access Server
PC User/DBA Viewpoints.
From the PC user's view, any computer beyond the PC is considered a
remote computer. But the DBA on the HP 3000 has a different view because
Access Server has to know where the data source is located--a database or
file on the host HP 3000 or remote HP 3000.
Figure 1-1 illustrates these two perspectives for host and remote HP 3000
systems.
The PC user sees local tables and remote tables. Because of the
transparency provided by Access Server, remote means anything beyond the
PC.
The DBA, on the other hand, configures tables from host databases or
files and remote databases or files, or some combination of these. For
the DBA, remote means any HP 3000 connected to the host system.
Thus, the PC user's remote tables are derived from host databases or
files, or remote databases or files, or some combination of these.
System Manager Viewpoint.
The System Manager's view includes the hardware environments. For Access
PC and Access Server, these include:
* The PC environment. Any peripherals attached to the personal
computer, and software used on the personal computer.
* Data communication from the PC to the host HP 3000. This is
either a LAN connection or a basic serial connection (RS-232/422
or X.25).
* The host HP 3000 environment. Host databases, files, peripherals,
and software.
* NS/3000 data communications. This is the link (either a direct
connection or a LAN connection) to remote HP 3000s. Over this
link, Access Server retrieves "networked" database or file
information.
* The remote computer environment. The remote computer environment
consists of a remote HP 3000 system, its software, and its data
sources.
All explanations in this tutorial (and in the Information Access Server:
Database Administration manual) are from the DBA's perspective.