gtpa3m18Application Requester User's Guide

Glossary of Terms Related to TPFAR

This glossary defines terms and concepts related to TPFAR in this book. If you do not find the term you are looking for, refer to the Index, the TPF Library Guide, or the Dictionary of Computing, ZC20-1699.

A

application requester (AR)
A DRDA component that transforms a database request into communication protocols for a distributed relational database system.

application server (AS)
A DRDA component that receives and processes database requests from an application requester.

B

bind process
A process in which a relational database management system transforms the specification of an SQL statement into a sequence of internal operations to optimize data retrieval.

C

column
A vertical arrangement of information in a table.

cursor
A control structure used by an application to retrieve and or update multiple rows in a table or to point to a row of interest within a table.

D

database management system (DBMS)
A software system that has a catalog describing the data it manages. The DBMS controls access to the data stored within it.

database request module (DBRM)
A DB2 data set member containing information about SQL commands. The DBRM is created by the precompiler and used in the bind process.

This file contains information on all SQL commands in the user application program. Included is information about how the SQL commands are executed and DB2's access strategy.

DB2
An IBM relational database management system for MVS operating systems.

Distributed Relational Database Architecture (DRDA)
A relational database connection protocol consisting of protocols for communication between an application and a remote database, and communications between databases.

H

HCT
Hotcon table.

hotcon
A hot conversation or hot connection, depending on the communication protocol used.

In LU 6.2, a TPF Advanced Program-to-Program Communications (TPF/APPC) conversation that remains allocated and active past the completion of the transaction. The TPF/APPC conversation parameters between the TPF Application Requester (TPFAR) and the DB2 system are saved in an entry in the hotcon table (HCT). When another entry control block (ECB) requests a conversation with the same remote application server, TPFAR reuses the active conversation.

In Transmission Control Protocol/Internet Protocol (TCP/IP), a TCP/IP connection that remains active past the completion of the transaction. The socket descriptors are saved in an entry in the hotcon table. When another entry control block (ECB) requests a connection with the same remote application server, the TPFAR reuses the active connection.

L

logical unit of work
A sequence of SQL commands that DB2 treats as a single entity.

logical unit of work identifier (LUWID)
An ID consisting of the fully qualified LU name, logical unit of work instance number, and logical unit of work sequence number that uniquely identifies a logical unit of work within the network.

P

package
An object containing a set of SQL statements that have been bound statically and are available for processing.

R

relational database (RDB)
A database in which the data are organized and accessed according to relations.

remote unit of work
A method of accessing distributed relational data in which users or applications can, within a single unit of work, read and update one system using multiple SQL statements.

row
A horizontal arrangement of information in a table.

S

SQLCODE
A system-dependent SQL return code.

SQLSTATE
A system-independent SQL return code field for the outcome of the last executed SQL command.

structured query language (SQL)
The programming language used to define relational data, access relational data, and control access to relational database resources.

SQL database management system directory (SDD)
A directory used by TPF to keep relational database (RDB) information. Most of this information is set up with the ZSQLD command.

structured query language communications area (SQLCA)
A structure that contains information about the execution of the SQL commands.

Systems Application Architecture (SAA)
A set of software interfaces, conventions, and protocols that provide a foundation for designing and developing consistent applications across systems.

T

table
A named data object consisting of a specific number of columns and some number of unordered rows.