Data Management Library Introduction to Pathmaker Abstract Part Number Edition Published Product Version Release ID Supported Releases This manual introduces the Pathmaker product. It defines basic Pathmaker terminology, suggests several approaches for successfully using the product, and describes how an application created with the Pathmaker product looks and behaves. 067867 Fourth September 1993 Pathmaker D20 D20.
Document History Edition Part Number Product Version Earliest Supported Release Published Fourth 067867 Pathmaker D20 C30/D10.00 September 1993 New editions incorporate any updates issued since the previous edition. A plus sign (+) after a release ID indicates that this manual describes function added to the base release, either by an interim product modification (IPM) or by a new product version on a .99 site update tape (SUT).
New and Changed Information The Introduction to Pathmaker manual has been completely restructured and rewritten for this release of the product. The previous version of this manual was written for the B41 version of the Pathmaker product; since that time, several new versions of the product have been released. This manual describes the product based upon the Release 3 D20 version of the Pathmaker product.
New and Changed Information iv 067867 Tandem Computers Incorporated
Contents About This Manual xi About the Pathmaker Manual Set Section 1 xiii Introduction to Pathmaker and Pathway Overview of Pathmaker 1-1 Benefits of Using Pathmaker 1-1 How Pathmaker is Used 1-2 Online Transaction Processing (OLTP) Applications 1-4 Functions Performed by OLTP Applications 1-6 Requirements of Online Transaction Processing 1-8 Overview of Pathway 1-9 Benefits of Using Pathway 1-9 How Pathway is Used 1-10 Creating Applications Without Pathway 1-10 Creating Applications With Pathway 1-1
Contents How Pathmaker Helps 1-26 Application Creation Assistance 1-26 Application Creation Tasks 1-27 Pathmaker Full Screen Interface Features 1-28 Pathmaker Application Definition Language (PMADL) Management Assistance 1-32 Application Design Assistance 1-33 Tandem Databases and TMF 1-34 Tandem Database Products 1-34 NonStop SQL 1-34 Enscribe 1-34 Enscribe DDL (Data Definition Language) 1-35 Database Types and Pathmaker 1-37 Pathmaker and the DDL Dictionary 1-37 NonStop SQL Table Registration 1-37 Databa
Contents Types of Pathmaker Applications 2-13 DB Requester Applications 2-13 Operating a DB Requester Application 2-14 Components of a DB Requester Application 2-16 Custom Applications 2-18 Operating a Custom Application 2-18 Components of a Custom Application 2-19 Other Capabilities 2-22 Accessing Pathway Applications From a Pathmaker Application Pathway Open Environment Toolkit (POET) 2-22 Section 3 2-22 Using Pathmaker—An Overview Major Pathmaker Components 3-1 Pathmaker Catalog 3-2 Full Screen Inter
Contents Glossary Glossary–1 Index Figures viii Index–1 Figure 1-1. The Pathmaker Product in the Development and the Production Environments 1-3 Figure 1-2. Online Transaction Processing Applications Figure 1-3. Functions of an OLTP Application Figure 1-4. Monolithic Application Figure 1-5. Requester-Server Application Figure 1-6. Creating an OLTP Application With Pathway (Without the Pathmaker Product) 1-15, 1-30 Figure 1-7. IPC Messages Figure 1-8.
Contents Tables Table 1-1. Comparison of NonStop SQL and Enscribe Products (Page 1 of 2) 1-38 Table 1-1. Comparison of NonStop SQL and Enscribe Products (Page 2 of 2) 1-39 Table 3-1.
Contents x 067867Tandem Computers Incorporated
About This Manual The Pathmaker product is a tool that assists in the creation of Pathway requesterserver applications for computer systems that use the Tandem NonStop Kernel. The Introduction to Pathmaker manual provides a comprehensive introduction to the Pathmaker product. The manual explains how an application created with the Pathmaker product looks and behaves, defines basic Pathmaker terminology, and suggests several general approaches for successfully using the product.
About This Manual Section 1, “Introduction to Pathmaker and Pathway,” introduces some of the benefits and features of the Pathmaker and Pathway products (including some of the features new for this release). This section also defines Pathway terminology and components and describes the main purpose of several related Tandem products. Section 2, “Pathmaker Applications,” explains the architecture of applications produced with the Pathmaker product.
About This Manual About the Pathmaker Manual Set The Pathmaker manual set for Release 3 consists of four Pathmaker manuals. Figure 1 is a documentation map that shows how the Pathmaker manuals are related to each other and to other Tandem manuals. The map, read from the top down, indicates the order in which the manuals should be read. Manuals grouped by brackets are corequisites. Figure 1.
About This Manual The following chart explains the purpose of each Pathmaker Release 3 manual and its intended audience: Pathmaker Manual Purpose Audience Introduction to Pathmaker Provides a comprehensive introduction to the Pathmaker product. This manual explains how an application created with the Pathmaker product looks and behaves, defines basic Pathmaker terminology, and suggests several general approaches for successfully using the product.
About This Manual Related Manuals The Pathmaker product interacts with several other Tandem products.
1 Introduction to Pathmaker and Pathway The first step to thoroughly understanding the Pathmaker product, is to understand the purpose of the product and how it works with other Tandem products. This section addresses these issues by: Introducing some of the benefits and features of the Pathmaker product. Describing online transaction processing (OLTP) applications. Discussing some of the benefits and features of the Pathway product and introducing Pathway terminology.
Introduction to Pathmaker and Pathway Overview of Pathmaker How Pathmaker is Used Application developers enter information about the application through the Pathmaker full screen interface, which provides a series of screen-based entry forms. (Information about the application can also be entered using the Pathmaker Application Definition Language (PMADL), which is a syntax-based interface.) The Pathmaker product stores the information and later uses it to generate code for the application.
Introduction to Pathmaker and Pathway Overview of Pathmaker Figure 1-1 shows how the Pathmaker product fits in a development environment (top) and how the application it generates fits in a production environment (bottom). Figure 1-1.
Introduction to Pathmaker and Pathway Online Transaction Processing (OLTP) Applications Online Transaction It is essential to understand some basic information about the OLTP environment and Processing (OLTP) about the Pathway product before learning more about using the Pathmaker product. Applications This subsection explains the basic OLTP environment and some of its features and functions and describes Pathway and the various components it supports in the OLTP environment.
Introduction to Pathmaker and Pathway Online Transaction Processing (OLTP) Applications Prior to the advent of computers, business was conducted in a transaction fashion and every transaction was accomplished from start to finish (that is, a bank deposit was initiated and then immediately completed). When computers were introduced, many transactions were gathered during the business day and later processed together.
Introduction to Pathmaker and Pathway Online Transaction Processing (OLTP) Applications Functions Performed by OLTP Applications All OLTP applications perform these basic functions: Display and accept transaction data. Perform input validation and allow the end user to correct input errors. Immediately update the database to reflect how the new transaction data affects the business.
Introduction to Pathmaker and Pathway Online Transaction Processing (OLTP) Applications Figure 1-3. Functions of an OLTP Application Function 1. Application displays Vehicle Registration Screen. Function 2. End user enters transaction data and presses function key to signal the application to add vehicle information.
Introduction to Pathmaker and Pathway Online Transaction Processing (OLTP) Applications Requirements of Online Transaction Processing Typically, online transaction processing applications must do the following: Handle multiple users performing related jobs such as simultaneous order entries. Handle concurrent requests to modify or retrieve the same information. Handle requests from different types of input devices, located at different geographic sites.
Introduction to Pathmaker and Pathway Overview of Pathway Overview of Pathway Pathway is a Tandem product that supplies the tools and environment that assist in the creation and running of OLTP applications. Because the Pathmaker product's main purpose is to help create Pathway applications, a working knowledge of basic Pathway concepts and terminology is a prerequisite to understanding the Pathmaker product. Benefits of Using Pathway There are two primary benefits gained by using the Pathway product.
Introduction to Pathmaker and Pathway Overview of Pathway How Pathway is Used The Pathway product is used for two primary activities: Creating applications based on the requester-server model Running requester-server applications These two activities, and the Pathway components that support them, are explained in detail in this subsection.
Introduction to Pathmaker and Pathway Overview of Pathway Creating Applications With Pathway The OLTP cycle is basically a two-phase operation. First, input data is collected from the end user and then the collected data is used to read from or update the database. When the transaction processing cycle is examined, it becomes clear that a more effective way to develop an application is possible.
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-5. Requester-Server Application Vehicle Registration Application Display Screen Send Request Service 3 Service Service 2 Service 1 Requester Accept Commands and Data Return Reply IPC messages Write Vehicle Owner Read Server License Database Terminal Management Database Management 1. Display blank vehicle registration screen. 2. Accept new vehicle data and perform preliminary input validation. 3. Send request with vehicle data.
Introduction to Pathmaker and Pathway Overview of Pathway Requester Functions A requester is an interactive program that displays and manages transaction data on the end user’s terminal screen. In this capacity, a requester performs these functions: Provides the data entry screens for the application terminal. Accepts data entered at the terminal. Performs preliminary input validation. Builds a request message from the accepted data.
Introduction to Pathmaker and Pathway Overview of Pathway Benefits of Using Requesters and Servers Terminal processing and database access are two operations performed by an OLTP application that have very little in common. Therefore, splitting the online application into a terminal handler and a database handler is useful because it is a logical way to modularize an application. Also remember these points: Applications written in modular format are easier to write, control, and maintain.
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-6 illustrates how a requester-server application is created with Pathway (without using the Pathmaker product). The application developer uses TEDIT to create requester source code, server source code, and the files that will be used to configure and start the finished application. The source code is compiled and stored in the appropriate location. Figure 1-6.
Introduction to Pathmaker and Pathway Overview of Pathway Communication With IPC Messages Requesters and servers (and the services the servers contain) communicate with each other through interprocess communication messages (commonly referred to as IPCs). There are two types of IPC messages: request and reply. Request Messages Request messages are sent from a requester and received by a particular service.
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-7 illustrates communication using IPC messages between a requester and a server containing a List Vehicle by Vehicle ID Service. Figure 1-7. IPC Messages Request IPC Message (Vehicle ID) Requester List Vehicle by Vehicle ID Service Reply IPC Message (Vehicle Type, Year, Make, Model, and so on or Error Message) Server 1. End user fills in vehicle ID number. 2. End user presses function key for List Vehicle by Vehicle ID. 3.
Introduction to Pathmaker and Pathway Overview of Pathway Running Applications With Pathway The preceding discussion presented the definitions and functions of a requester, a service, and a server and explained how these components of a Pathway OLTP application are created (without the Pathmaker product). This subsection examines the various components of a running Pathway system. Process In a Tandem computer system, a process is essentially any running program.
Introduction to Pathmaker and Pathway Overview of Pathway Database A database is an organized collection of information stored in a structured format on a disk. The database is created by an individual using NonStop SQL or Enscribe. Service A service is a portion of database access code written in COBOL85 or C to perform a specific business task (transaction). Pathway applications created with the Pathmaker product use the concept of services.
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-8.
Introduction to Pathmaker and Pathway Overview of Pathway Server Class A server class is a named family of identical server processes, each of which is created from the same object file on disk. Server classes are created by Pathway at run time. The purpose of identical server processes is to maximize the performance of an application by fully utilizing the processing power of a Tandem system.
Introduction to Pathmaker and Pathway Overview of Pathway Context-Free Services As stated earlier, the ultimate destination of a Request IPC message is a service within a server. Several copies of a server process and, therefore, several copies of the services it contains can run concurrently. Each time a service is needed, any one of the available copies of the server that contains that service may be used (usually the least busy one).
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-10 illustrates a series of related transactions. Figure 1-10. Context-Free Services Server Class A 8 Service 1 10 Baines #7563 7 B 2 Boogle, Jane, 5 Fenz Rd., #2136 Service 2 9 Service 3 Server A Process 1 3 Service 1 Service 2 10 5 Service 3 Requester 6 Database Server A Process 2 1 End User Service 1 5 Service 2 Baines, Malcolm, 123 Main, #7563...
Introduction to Pathmaker and Pathway Overview of Pathway 5. The service returns BAINES, MALCOLM, 123 MAIN , ID # 7563 to the requester, which displays this information to the end user. Second Transaction: 6. The end user continues the listing by pressing the appropriate function key again. 7. The requester (working with the TCP) again invokes Service 2, passing the name BAINES and the associated identification number back to the server class containing server processes that contain Service 2. 8.
Introduction to Pathmaker and Pathway Overview of Pathway Figure 1-11 illustrates the components provided by Tandem that are used to create and run a Pathway OLTP application. Figure 1-11.
Introduction to Pathmaker and Pathway How Pathmaker Helps How Pathmaker Helps The Pathmaker product is a tool that helps create requester-server Pathway applications for computer systems that use the Tandem NonStop Kernel. Before the Pathmaker product was introduced, Pathway applications were often created manually. The requesters and servers were hand-coded (written from the beginning or modeled after an existing program).
Introduction to Pathmaker and Pathway How Pathmaker Helps Application Creation Tasks Some of the tasks an application developer performs to create a Pathway application with the Pathmaker product include: Describing the data that the application will use. Directing the Pathmaker product to generate SQL database access statements for inclusion in the server code. Writing the service code. Grouping services into servers.
Introduction to Pathmaker and Pathway How Pathmaker Helps Pathmaker Full Screen Interface Features Other Pathmaker full screen interface features used during the development of an application include: Help screens that provide information about the purpose of the Pathmaker screens and the legal values that can be entered in the screen fields. Ability to incorporate additional code into the requesters and servers that the Pathmaker product generates.
Introduction to Pathmaker and Pathway How Pathmaker Helps Pathmaker Application Definition Language (PMADL) In addition to the full screen interface, the Pathmaker product also provides PMADL, which is a syntax-based interface. PMADL can help an application developer quickly make mass changes to the components of a Pathmaker application; it is also useful for quickly creating a Pathmaker application that is similar to an existing Pathmaker application.
Introduction to Pathmaker and Pathway How Pathmaker Helps Figure 1-12 illustrates the process of creating a Pathway application with the Pathmaker product. Compare Figure 1-12 to Figure 1-6 (repeated from a previous page for your convenience), which shows creating a Pathway application without the Pathmaker product. Figure 1-6.
Introduction to Pathmaker and Pathway How Pathmaker Helps Figure 1-12.
Introduction to Pathmaker and Pathway How Pathmaker Helps Management Assistance The Pathmaker product not only makes developing a Pathway application simpler, it also makes preparing, controlling, tracking, and managing an application development effort easier. This is especially important for large application development efforts involving many people.
Introduction to Pathmaker and Pathway How Pathmaker Helps Application Design Assistance One way that the Pathmaker product helps with application design is by providing a simulation feature. Using the simulation feature, application screens and the navigation among them can be previewed before any code exists.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Tandem Databases This subsection discusses the Tandem database management products and the and TMF Transaction Monitoring Facility (TMF) product, which helps ensure the integrity of data. This discussion will focus on how these products interact with and affect the Pathmaker product. Tandem Database Products Tandem offers two database management products: the NonStop SQL product and Enscribe.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Enscribe DDL (Data Definition Language) Enscribe DDL is one of the Tandem Encompass products. As its name implies, DDL is a language used to define data. The language consists of: Statements to define data Commands to control how those statements are compiled DDL is also a program that compiles the data definitions and generates output from the compiled definitions.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Updating the Enscribe DDL Dictionary. Another use of Enscribe DDL is to update the DDL dictionary. The DDL dictionary is an actual database that contains the formal description of the data in accordance with the data definitions in a schema.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Database Types and Pathmaker Basically, all Pathmaker applications are built in the same way, regardless of whether they will be accessing data in a NonStop SQL database or in Enscribe files. The area most affected by the choice of database is the creation and compilation of service and server code.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Table 1-1 compares some of the features and uses of the NonStop SQL and Enscribe products. Table 1-1. Comparison of NonStop SQL and Enscribe Products (Page 1 of 2) How data is stored How database is created NonStop SQL Enscribe Tables on disk.* (A special set of tables, called an SQL catalog, holds information describing these tables.) Database must exist before the Pathmaker product is used, although tables can be empty.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Table 1-1. Comparison of NonStop SQL and Enscribe Products (Page 2 of 2) How database and other application structures (IPC messages and so forth) are described to Pathmaker How database is accessed by a server NonStop SQL Enscribe Application developer: 1. Registers SQL tables with Pathmaker screen. 2.
Introduction to Pathmaker and Pathway Tandem Databases and TMF Database Creation As stated earlier, a production database is normally created and controlled by a specially authorized individual in a business, such as a database administrator. For testing purposes, the Pathmaker product provides a utility program named PMPROJECT that can assist in creating Enscribe files. The NonStop SQL product must be used to create a test SQL database.
Introduction to Pathmaker and Pathway Tandem Databases and TMF How to Protect an Application Using TMF In the requester code, the SCREEN COBOL verb BEGIN-TRANSACTION identifies the start of a TMF transaction. The END-TRANSACTION verb indicates that the transaction is complete and changes to the database should be committed; that is, the changes resulting from the transaction are permanent and will not be undone by the TMF product.
2 Pathmaker Applications An important part of understanding the Pathmaker product is knowing how an application produced with the product looks and behaves. This section helps you gain this knowledge by: Explaining the architecture of an application produced with the Pathmaker product. Describing how an end user operates an application produced with the Pathmaker product. Discussing ways that an application developer can customize a Pathmaker application.
Pathmaker Applications The Architecture of a Pathmaker Application The function key list displays the function keys that are available and their associated action. (The list shown on the screen may include only a portion of the available keys.) The function key list is usually located near the bottom of the screen. The message area is a reserved portion of the screen where messages and errors are displayed. The message area is usually below line 24 of the screen.
Pathmaker Applications The Architecture of a Pathmaker Application Figure 2-1.
Pathmaker Applications The Architecture of a Pathmaker Application Function Key Actions Each Pathmaker requester screen can utilize many function keys. In a Pathmaker application, pressing a function key initiates one, and only one, action. The actions available are as follows: Processing: Invoke a service to perform a specific task (usually after data has been entered on the screen). Execute additional SCREEN COBOL requester code added by the application developer.
Pathmaker Applications The Architecture of a Pathmaker Application Figure 2-2. Requester Help Screen Help for: Department 905 Employee Information Page 1/2 This screen is used to maintain a test database concerning employees in Dept. 905 EMPLOYEE NUMBER This field is a unique four-digit value that identifies an employee. SALARY GRADE A two-digit number from 01 to 79.
Pathmaker Applications The Architecture of a Pathmaker Application Data Field Attributes Each data field can have certain attributes that determine how the field will look and act. These attributes can include: Length Data type Default value Allowable values (for example, must be “A,” “B,” or “C”) Video attributes (for example, bright, blinking, reversed) Protection from data entry Display format (picture)—for example, $99.
Pathmaker Applications Operating a Pathmaker Application Operating a Pathmaker Application Entering Data When an end user operates an application created with the Pathmaker product, the application functions in certain predictable ways. These include the way that data entered by the end user is handled, the way default values are displayed, the way data and messages received from the servers are processed, and the way that the end user is allowed to navigate among screens in the application.
Pathmaker Applications Operating a Pathmaker Application Figure 2-3 shows an example of a requester screen containing a data entry error. The underlined areas represent unprotected fields where data is entered or displayed. Text in italics represents data entered by the end user. In this example, the employee number field must contain a valid number before an insert (F10) can be initiated. Figure 2-3.
Pathmaker Applications Operating a Pathmaker Application Figure 2-4 shows how a requester screen looks after an attempt is made to insert a row with an employee number that is already in the database. The underlined areas represent unprotected fields where data is entered or displayed. Text in italics represents data entered by the end user. Figure 2-4.
Pathmaker Applications Operating a Pathmaker Application Figure 2-5 illustrates an application with a hierarchical structure. In this example, to get to Requester “E” from the Main Menu, the end user first presses F4 to go to Requester “C” and then, from that screen, presses F5 to go to Requester “E.” Figure 2-5.
Pathmaker Applications Customizing Pathmaker Applications Customizing Although the Pathmaker product creates an application with a certain predetermined Pathmaker architecture, it provides many ways to customize that application to meet end user Applications specifications. Screen Layout For each requester, the Pathmaker product can create the initial layout for the end user’s screen based on the type of requester chosen and on the attributes specified on Pathmaker screens.
Pathmaker Applications Customizing Pathmaker Applications Help Text When application developers create requesters with the Pathmaker product, one of their tasks is to write and enter the text that will appear on the end user’s help screen. The Pathmaker product handles all of the complexities of storing and displaying the information to the end user in the appropriate format.
Pathmaker Applications Types of Pathmaker Applications Types of Pathmaker There are two types of applications that can be produced with the Pathmaker product: Applications Database (DB) requester applications (sometimes referred to as simple applications because they are simple to create) Custom applications Although Pathmaker applications used in production are often combinations of these two types, this manual and the other manuals in the Pathmaker Release 3 library address DB requester applications and
Pathmaker Applications Types of Pathmaker Applications Operating a DB Requester Application A DB requester application uses keys to locate specific rows (records) in a database. Three categories of keys exist for NonStop SQL tables: Primary keys Indexes SYSKEYs Three categories of keys exist for Enscribe files: Primary keys Alternate keys Courtesy keys DB requester applications generally use primary keys and indexes (alternate keys) to locate information in the database.
Pathmaker Applications Types of Pathmaker Applications Figure 2-6 provides an example of a screen from a DB requester application used to maintain information about fictitious employees in a test database. Figure 2-6.
Pathmaker Applications Types of Pathmaker Applications Components of a DB Requester Application A DB requester application is composed of: One or more DB requesters that application developers create using the Pathmaker product The standard services and servers provided by the Pathmaker product One or more menu requesters that application developers create using the Pathmaker product (optional) It is possible to create a DB requester application that accesses: Only one table or file (a single-file DB reque
Pathmaker Applications Types of Pathmaker Applications Menu Requester. A menu requester displays a screen to the end user composed of a list of function keys that are used solely to navigate to other requesters. Menu requesters can be used with both DB requester applications and custom applications. A Menu requester cannot invoke a service. Figure 2-7 shows an example of a menu screen. Figure 2-7.
Pathmaker Applications Types of Pathmaker Applications Custom Applications The second type of application that can be produced with the Pathmaker product is a custom application. Custom applications are created to handle the crucial data processing needs of a business, including high volume OLTP applications.
Pathmaker Applications Types of Pathmaker Applications Figure 2-8 is an example of a screen for a custom application used to maintain vehicle information. Figure 2-8.
Pathmaker Applications Types of Pathmaker Applications Transaction (TRNS) Requester. A transaction (TRNS) requester displays a screen similar in appearance to the screen for a DB requester. The important difference is that an end user can only invoke a custom service by using a transaction requester. Note Transaction requesters cannot use the standard services. Custom Service. A custom service can perform database access, data manipulation, editing, and calculations.
Pathmaker Applications Types of Pathmaker Applications The Pathmaker product supplies a common service utility library that contains functions, constants, and definitions that can be referenced by code in a custom source file. The common service library includes constants for common Enscribe and NonStop SQL file system error codes, and functions for formatting error messages, manipulating certain character strings, and so on.
Pathmaker Applications Other Capabilities Other Capabilities In addition to creating Pathway requesters and servers, the Pathmaker product has other capabilities. This subsection briefly introduces these capabilities and, where appropriate, provides references to manuals containing additional information. Accessing Pathway Applications From a Pathmaker Application It is possible for a Pathmaker application to access a Pathway application built outside the Pathmaker product.
3 Using Pathmaker—An Overview In the two previous sections, the benefits and features of the Pathmaker product and other related Tandem products, the types of Pathmaker applications that can be produced, and how Pathmaker applications look and behave were explained. In this section: The major Pathmaker components are introduced. The term Pathmaker project is defined. Several general approaches for using the product are discussed. The phases of a formal Pathmaker application life cycle are suggested.
Using Pathmaker—An Overview Major Pathmaker Components Figure 3-1 illustrates the major components of the Pathmaker product. Figure 3-1.
Using Pathmaker—An Overview Major Pathmaker Components Full Screen Interface The Pathmaker full screen interface is, itself, a running Pathway system composed of requesters, server processes, server classes, and other Pathway entities. The full screen interface is used to enter information into a Pathmaker catalog. The interface presents a series of screens where information about the requesters, services, and servers that make up an application is entered by application developers.
Using Pathmaker—An Overview Major Pathmaker Components Utilities The Pathmaker product also includes several utilities, as follows: PMINSTAL, which assists in the installation of the Pathmaker product on a development system. HELPUTIL, which is used to modify the help text for an application created with the Pathmaker product. PMPROJECT, which is used to create and manage Pathmaker projects. (The term Pathmaker project is defined in the next subsection.
Using Pathmaker—An Overview A Pathmaker Project A Pathmaker Project Project is a term that has several different meanings. A project can be thought of as all the files needed to complete an application development effort using the Pathmaker product.
Using Pathmaker—An Overview A Pathmaker Project Figure 3-2.
Using Pathmaker—An Overview A Pathmaker Project Project Catalog During the preparation for a Pathmaker application development effort, Pathmaker software is installed on the development system and one or more Pathmaker projects are added. When a Pathmaker project is added, a special group of files called a Pathmaker project catalog is created for that particular project.
Using Pathmaker—An Overview A Pathmaker Project Project Subvolume The project catalog resides on the project subvolume, which is specified when the project is first added to the development system. In addition to the project catalog files, each project subvolume also contains several other files associated with a particular project. The contents of a project subvolume are illustrated in Figure 3-3.
Using Pathmaker—An Overview Approaches for Using Pathmaker Approaches for Using The Pathmaker product was designed to provide application developers and designers Pathmaker with a great deal of flexibility. This flexibility allows the product to be used in different ways for different situations.
Using Pathmaker—An Overview Approaches for Using Pathmaker There are several advantages to designing screen layouts after data for the application has been defined in the Pathmaker catalog. These advantages are as follows: Allowing the Pathmaker product to create the data fields and their associated headings on requester screens from information in the catalog is much faster than painting alone and allows the requester to be used for a production application with much less modification.
Using Pathmaker—An Overview Approaches for Using Pathmaker Simulating the appearance of the application screens and navigation among those screens is an important feature of the Pathmaker product that can be used during the design of an application, as well as during the development of an application. Potential end users can view the user interface and provide valuable feedback early in the application life cycle.
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application A Suggested Because the Pathmaker product is designed to be flexible, it does not always dictate a Life Cycle for a fixed order for completing the tasks involved in a Pathmaker application development Pathmaker Application effort. While this flexibility is often an advantage, it could cause confusion for first time Pathmaker users or for project teams that consist of many members.
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application Design The next phase is application design in which a design specification is created. The design specification is a written document that states the solution to the end user’s business problem, which was identified in the definition phase. This document will become the focal point for application developers using the Pathmaker product.
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application Description of each requester in this application, including: Name of the requester Screen layout End user’s terminal type Function keys to be used and their associated actions Data the requester expects to receive as parameters Data the requester must send to each service invoked (request message) Data the requester must pass as parameters to each requester invoked Help text for end user Service packaging information Name of th
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application Setup This phase focuses on preparing the Pathmaker environment to implement the design. Tasks during this phase include: Installing Pathmaker software Installing related products (TMF, Enform, and so on, if necessary) Assigning logons and subvolumes Preparing DDL schema Setting up the test database. (This can occur later for Enscribe files only.
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application Documentation During this phase (which should be done in parallel with development), information about the implemented application is recorded. This information will be used for training, maintenance, and auditing purposes and to track the progress of application development.
Using Pathmaker—An Overview A Suggested Life Cycle for a Pathmaker Application Table 3-1. Life Cycle of a Pathmaker Application Phase Objective Input Output Pathmaker Feature Definition To clearly define the business problem. Information from end users Problem specification Design To describe the overall solution. Problem specification Designer ideas End user feedback Design specification Planning To plan resources for implementing design.
Using Pathmaker—An Overview A Final Note A Final Note With the completion of the Introduction to Pathmaker manual, you have gained a foundation of basic knowledge about the Pathmaker product that will enable you to effectively use the information presented in the Pathmaker Programming Guide and the Pathmaker Reference Manual.
Glossary application. A set of programs designed to perform a specified task, usually involving operations on a database. application developer. A programmer using the Pathmaker product or some other means to create an application. application screen. The data entry screen or menu screen for an application. Application screens are displayed to end users when they run a Pathmaker application.
Glossary data field area. On a Pathmaker default screen, the area between the two rows of equal signs that contains all of the data fields and the headings that identify them. data field attribute. A characteristic of a data field. Data field attributes can include: length, data type, default value, allowable values, video attributes, protection from data entry, display format, heading, upshifting of entered data, and help text. data type. A category of data.
Glossary developer. See application developer. Encompass. A set of data management products offered by Tandem that includes the DDL, Enscribe, Transfer, Pathway, TMF, and Enform products. end user. A person running a target application generated by the Pathmaker product. Enform. A Tandem product that generates reports from information contained in a DDL dictionary. Enscribe. A Tandem software product that provides high-level access to, and manipulation of, records in an Encompass database.
Glossary hierarchical structure. The screen navigation structure that the Pathmaker product uses when creating an application. In an application with a hierarchical structure, the application's requesters are arranged in a fixed hierarchy, sometimes referred to as a tree. Typically, this hierarchy has a main menu requester at the top level with submenu requesters below leading to detail requesters (used for data entry or data retrieval) at the lowest levels. host language.
Glossary monolithic application. A single program that performs all terminal handling, communications, and database management operations. multifile DB requester. A type of Pathmaker DB requester that accesses multiple related tables or files. NonStop SQL. The Tandem implementation of a distributed SQL (structured query language) relational database management system. object. See Pathmaker object. OLTP (online transaction processing) application.
Glossary Pathway. A Tandem product that helps simplify the development and control of online transaction processing applications. Pathway includes SCREEN COBOL for requester development, terminal control processes (TCPs) that use the SCREEN COBOL code to control terminals, PATHMON for central control of all processes, and the PATHMON command interpreter. Pathway command file. A file containing commands that define and add the Pathway objects required to execute an application.
Glossary registered (REG) service/server. A service or server written outside of the Pathmaker environment but known to a Pathmaker project. It is possible to create a Pathmaker application that accesses outside servers without registering them; however, registering them allows the Pathmaker product to move their associated files during import and export operations.
Glossary request message. A type of interprocess communication (IPC) message sent from a requester and received by a particular service. When an end user presses a function key associated with a business task, the requester formats a message that identifies the service and includes the data needed by the service to do its work. A request message is initiated in the SCREEN COBOL requester code by a SEND statement. Pathway routes the request to a server process containing the desired service. schema.
Glossary service skeleton. A file, consisting of source text lines plus special macro language command lines, that the Pathmaker product uses to generate C service source code. single-file DB requester. A type of Pathmaker DB requester that accesses only one table or file. simulation. The displaying of sequences of screens that provides a preview of an application in its final form. Through simulation, end users can see what an application will look like before it is actually coded and installed.
Glossary transaction. A group of computer operations that reflect a particular commercial interaction by changing a database from one consistent state to another consistent state. These operations, including the entry of data about the event, the processing of that data, and the resulting change in the database, provide a computer model of the real events making up the transaction.
Index A Application definition of 1-4, Glossary-1 design features of Pathmaker 1-33 developer 1-15, 1-26, 1-27, Glossary-1 life cycle 3-9 definition phase 3-12 design phase 3-13 development phase 3-15 documentation phase 3-16 maintenance phase 3-16 planning phase 3-14 production phase 3-16 setup phase 3-15 testing phase 3-16 monolithic 1-10 OLTP (online transaction processing) creating with Pathway 1-11, 1-15 definition of 1-4 functions of 1-6 processing requirements of 1-8 running with Pathway 1-18 Pathmak
Index C C custom service 2-20 Catalog 1-26, 3-2, 3-7 reports 1-32 subvolume 3-8 Client/transaction server applications 2-22 COBOL85 custom service 2-20 definition of Glossary-1 Code generators 3-3 Code macros 1-32, 3-3 Code sharing 1-32, 3-3 Command files See Pathway, command files Common service utility library 2-21 Communication message 1-11, 1-16 Configuration file 1-15, 1-25, 1-27, 1-30 Context-free service 1-22 Copy libraries 3-3 Custom application components 2-19 operation 2-18 screen 2-19 Custom ser
Index Database comparison of Enscribe and NonStop SQL 1-38 creation 1-40 definition of 1-19 effect on Pathmaker 1-37 Enscribe creating 1-35 definition of 1-34 keys 2-14 NonStop SQL definition of 1-34 keys 2-14 table registration 1-37 types 1-34 Database requester See DB requester DB requester application 2-13 components 2-16 keys 2-14 operation 2-14 screen 2-15 multifile and single-file 2-16 DDL (Data Definition Language) definition of 1-35, Glossary-2 dictionary 1-36, 1-37 schema 1-35, 1-37 Decoration 2-1
Index E Encompass 1-34, Glossary-3 End user Glossary-3 End user screen 1-2, 2-1, 2-9, 2-11, 3-9 END-TRANSACTION statement 1-41 Enform definition of Glossary-3 reports 1-32 Enscribe comparison with NonStop SQL 1-38 creating a database with 1-35 DDL See DDL definition of 1-34 keys 2-14 F File Utility Program See FUP Full screen interface 1-2, 1-28, 3-3 Function key list 2-1 FUP creating Enscribe files with 1-35 definition of Glossary-3 G General server 2-16 Generated source file 2-21 H Heading Glossary-3 Hel
Index I Interface for Pathmaker 1-2, 1-28, 1-29, 1-32, 3-3 Interprocess communication message See IPC IPC 1-11, 1-16 J Japanese character set 2-1 JET6530 terminal 2-1, Glossary-4 K Kanji 2-1, Glossary-4 Keys 2-14 L Language See Programming language Life cycle 3-9 definition phase 3-12 design phase 3-13 development phase 3-15 documentation phase 3-16 maintenance phase 3-16 planning phase 3-14 production phase 3-16 setup phase 3-15 testing phase 3-16 M Macro language 1-32, Glossary-4 Macros 1-32, 3-3 Mainten
Index Message area 2-1 from a Pathmaker application 2-8 interprocess communication (IPC) 1-11, 1-16 N NonStop SQL comparison with Enscribe 1-38 definition of 1-34 keys 2-14 statement generation 1-26 table registration 1-37 O Object 3-7 OLTP application creating with Pathway 1-11, 1-15 definition of 1-4, Glossary-5 functions of 1-6 processing requirements of 1-8 running with Pathway 1-18 Online processing 1-4 Online transaction processing application See OLTP application Overlay 2-2 P Page 2-2 Paging area 2
Index Pathmaker application (continued) DB requester 2-13 displaying defaults 2-8 entering data 2-7 function key actions 2-4 function key list 2-1 help text 2-4, 2-12 hierarchical structure 2-9 Kanji support 2-1 life cycle 3-9, 3-12 message area 2-1 messages 2-12 operating 2-2, 2-7 overlay 2-2 page 2-2 paging area 2-2 prototype 2-13, 3-11 receiving data and messages 2-8 screen design 3-9 screen layout 2-1, 2-11 screen navigation 2-9 screen painter 2-11 screen preview 1-2 terminal 2-1 title area 2-1 applica
Index Pathmaker (continued) large development team support 1-2 macro language 1-32 macros 1-32, 3-3 management assistance 1-32 manual set xiii manuals for related products xv object 3-7 PMADL 1-2, 1-29, 1-32, 3-3 production application creation 3-9 project 3-2, 3-5 project catalog 3-7 project subvolume 3-8 reports 1-32 simulation 1-33, 3-10 skeleton files 3-3 SQL statement generation 1-26 subvolume 3-8 target application 3-5 terminal application developer 3-3 end user 2-1 TMF requirements 1-41 user interfa
Index Pathway (continued) how used 1-10 interprocess communication message (IPC) 1-11, 1-16 running an application with 1-18 Pathway Open Environment Toolkit See POET Planning phase 3-14 PMADL 1-2, 1-29, 1-32, 3-3 PMINSTAL utility 3-4 PMPROJECT utility 1-40, 3-4 POBJCOD file 1-18 POBJDIR file 1-18 POBJSYM file 1-18 POET, relationship with Pathmaker 2-22 Previewing screens See Simulation Process definition of 1-18 server 1-19 Production application See Pathmaker application Production phase 3-16 Programming
Index Requester 1-11 benefits 1-14 copy library 2-4, Glossary-7 DB See DB requester definition of 1-13 functions of 1-13 menu 2-17, 2-19 programming language See SCREEN COBOL registered (REG) 2-22 SCREEN COBOL library 1-18 skeleton 1-2, 3-3, Glossary-7 transaction (TRNS) 2-20 Requester-server application See OLTP application S Schema 1-35, 1-37 SCOBOL See SCREEN COBOL SCOBOLX compiler 1-13 Screen 1-2, 2-1, 2-9, 2-11, 3-9 SCREEN COBOL compiler 1-13 definition of 1-13 library 1-13, 1-18 Screen interface 1-2,
Index Service benefits 1-14 context-free 1-22 criterion for packaging 1-13, 1-14 custom 2-20 definition of 1-14, 1-19 functions of 1-14 registered (REG) 2-22 skeleton 1-2, 3-3, Glossary-9 SQL statement generation 1-26 standard 2-16 Setup phase 3-15 Shared code 1-32, 3-3 Simulation 1-2, 1-33, 3-10 Skeleton files 1-2, 3-3 language 1-32 SQL See NonStop SQL Standard service 2-16 Statement generation, NonStop SQL 1-26 T Table registration, NonStop SQL 1-37 Target application 3-5 terminal 2-1, Glossary-9 TCP 1-1
Index TMF BEGIN-TRANSACTION statement 1-41 database consistency 1-40 definition of 1-40 END-TRANSACTION statement 1-41 functions of 1-40 protecting an application with 1-41 requirements for Pathmaker 1-41, 3-7 Transaction 1-4 Transaction (TRNS) requester 2-20 Transaction copy library Glossary-10 Transaction Monitoring Facility See TMF U User interface 1-2, 1-28, 1-29, 1-32, 3-3 Utilities HELPUTIL 2-12, 3-4 PMINSTAL 3-4 PMPROJECT 1-40 V Video attribute 2-6, 2-8, 2-11, Glossary-10 Special characters $RECEIVE
