User guide

7 ENFORM Servers
058058 Tandem Computers Incorporated 7–1
This section describes how to write and use ENFORM servers — processes that can
supply data to the query processor as an alternative to the data being supplied directly
from a disc file (Figure 7-1). ENFORM servers extend ENFORM’s query capability by
enabling you to use data that might otherwise be unusable by the query processor.
Figure 7-1. ENFORM Server Process
Compiler/
Report
Writer
Dictionary
Data
Base
Query
Processor
Data
Base
Enform
Server
LIST
An ENFORM server can reside on the same or on a different system from the query
processor and can retrieve records from one or more data bases. However, query
performance might be enhanced if the server resides on the same system as the data
files the server reads.
An ENFORM server communicates through a series of interprocess messages with the
query processor and appears to the query processor as a data file.
The query processor’s access to an ENFORM server as a data file is limited to
sequential access only; that is, one record at a time, starting with the first record, then
the next and so on until the data is exhausted, or the query is satisfied. The query
processor must be able to open the server more than once and must be able to to access
the first and next records from the server repeatedly. There is no keyed or relative
access defined for ENFORM servers.