Introduction
The TPF Database Facility (TPFDF) is an IBM licensed program
product which provides database management capabilities for TPF or
ALCS applications. Traditionally, TPF or ALCS database management
functions are the responsibility of the applications programmer.
TPFDF increases programmer productivity by providing centralized
database handling routines so that application programmers only
need to understand the logical relationships of data, not the
physical characteristics.
The application program's independence of the physical database
also makes it easier to enhance TPFDF applications. In addition,
traditional files and TPFDF files can coexist in the same database,
and applications can wok with both traditional and TPFDF files.
Application Programmer Productivity Benefits
Typically, in traditional database handling, there is no
standard database organization. Therefore, there are no common
routines for data retrieval, searches, sorts, or updates.
Application programmers need to be aware of the physical size and
location of data.
TPFDF enforces a standard for database organization. For
example, it provides common routines to:
- Add, delete and modify data
- Read, sort and merge data
- Display data
- Read data from tape.
TPFDF provides high-level macros to act as an interface to these
common routines. Application programmers only need to know the
logical relationships of data, not the physical characteristics to
code these macros.
TPFDF also provides functions to allow a C language program to
access TPFDF file structures.
Database Administration Benefits
TPFDF enforces a centralized database structure that provides
many database administration benefits. Because the definition of
the database is centrally maintained, the database administrator
can modify database characteristics without affecting application
programs. This central maintenance, together with the utilities
that TPFDF provides, means that the database administrator can
- Check the integrity of the database
- Optimize application program performance
- Minimize application migration effort
- Minimize application enhancement effort
- Ease the migration process from a traditional database to a
TPFDF Database
- Easily implement the TPFDF Distributed Data Access feature
(TPFDF/DDA).
TPFDF installations need a database administrator to implement and
manage the physical database. It is the database administrators
responsibility to interface with both application and database
design.
Performance
TPFDF makes it possible to optimize application program
performance. For example, it allows physical data to be organized
to reduce direct access storage device (DASD) I/Os by:
- Selecting optimum physical record sizes
- Using an indexing method such as B+ Tree Indexing
TPFDF provides data collection tools for monitoring application
program performance. These tools can highlight ineffective database
design (excessive DASD I/Os, for example). The database
administrator can modify the database definitions to optimize
performance. One central change can improve the performance of many
application programs without any program modification.
Application Portability
TPFDF makes it easier to integrate new and existing
applications. Typically, when adding an application, there is some
data that both the existing and new applications need to
access.
Often, in a traditional database, the way the data is stored is
not compatible between the two applications (for example, the data
is held in different block sizes). This requires modification of
each new program that accesses the data.
With TPFDF, no program modification is needed. Block size
changes, and any other physical database changes, are transparent
to the application.
The application programs independence of the physical database
also makes it easier to enhance TPFDF applications.
Migration To TPFDF
TPFDF allows gradual migration from a traditional database:
- Traditional files and TPFDF files can coexist in the same
database.
- An application can work with both traditional and TPFDF
files.
- TPFDF macros and functions can retrieve and manipulate
traditional files.
This allows applications that use TPFDF to coexist with
applications that use traditional database handling methods.
Other TPFDF Benfits
- TPFDF is easy to install using TPF's System Initialization
Package (SIP), or SMP/E in an ALCS environments.
- Comprehensive hardcopy and softcopy documentation.
- Education (as a separate priced option).
TPFDF Features
The TPFDF Distributed Data Access (TPFDF/DDA) optional feature
allows data from TPFDF database to be propagated to a DATABASE 2
(DB2*) database using Structured Query Language (SQL) statements.
The SQL data can be collected from one or more TPFDF files, and
from one or more fields in each file.
The propagation process is transparent to the TPFDF application
program and is defined by the database administrator in centralize
database definitions.