Progress/400
Product Guide


The Client Schema Holder

The server schema on the AS/400 and the client schema holder are key components in the Progress/400 architecture. These components allow Progress 4GL applications to access DB2/400 database files by storing data definitions in an accessible format. WebSpeed and Open AppServer agents are clients to the Progress/400 DataServer, hence the information in this section also applies to them.

Creating a client schema holder involves the following general steps:

The schema holder need not reside on the client machine. For example, for ease of maintenance, you can locate the schema holder on a file server that multiple clients can access.

NOTE: A single schema holder can hold schemas for several non-Progress databases. In addition, it can hold the schema for one Progress database.

Creating an Empty Progress Database

The Progress/400 environment uses the empty database on the client to create a schema holder for your DB2/400 data definitions.

There are four ways to create an empty Progress database:

See the Progress Database Administration Guide and Reference for information on these techniques.

This section describes how to create a database with the Data Administration tool. Follow these steps to create and connect an empty Progress database on your client machine:

  1. Start the Progress desktop with no database connected and access the Data Administration tool.
  2. From the main menu, choose Database Create. The Create Database dialog box appears:
  3. Type the schema-holder name (for example, as4sh) in the New Physical Database Name field. This name must be different from the server schema library on the AS/400.
  4. Activate the An EMPTY Database radio button.
  5. Choose OK. The Connect Database dialog box appears. By default, the name of the newly created database appears in the Physical Name field.
  6. You do not need to provide any additional connection information. You can add connection parameters when you create the database or edit connection information later. See the online help for a complete description of the Connect Database dialog box.

    If you choose to add a logical database name in the Logical Name field, use the logical database name to refer to the database in your programming applications. For more information on database names, see the database access chapter in the Progress Programming Handbook.

  7. Choose OK to connect the empty Progress database and return to the Data Administration main window.

Next, run the Create DataServer Schema utility.

Creating the Client Schema Holder

Before you can create the client schema holder, you must:

Follow these steps to create the schema holder:

  1. Connect to an empty Progress database.
  2. From the Data Administration main menu, select DataServer DB2/400 Utilities Create DB2/400 DataServer Schema.
  3. The following dialog box appears:

  4. Type the name of the library that contains the server schema in the Dictionary Library Name field.
  5. Add logical database name information. A logical database name is a database reference that represents the name of a connected physical database. Progress uses the logical database name to resolve database references. When a procedure is compiled against a database, Progress stores the logical database name in the procedure’s r-code. When a procedure executes, its database references must match the logical name of a connected database.
  6. In the Code-Page field, type the name of the code page that the DB2/400 database files use (for example, IBM500). By default, the code page is IBM037.
  7. If your DB2/400 database files use a code page that Progress does not support, you must supply a conversion table in the CONVMAP.DAT file on the client. This file translates between the Progress client code page and the code page that the DB2/400 database files use.

    See the "User-defined Collation Tables" section in "System Administration," for more information on how the DataServer handles code pages and code-page conversion tables. For a complete discussion of code pages, see the Progress Internationalization Guide and the AS/400: National Language Support Planning Guide .

  8. Enter the information that your network protocol requires, as Table 3–2 describes.
  9. Table 3–2: Network Connection Parameters 
    Protocol
    Required Connection Parameters
    SNA
    Host Name: host-name
    Service Name: as400sna
    Service Name: server-name.progress-library-name
    Username: username
    Password: password
    TCP/IP
    Host Name: host-name
    Network: tcp
    Service Name: service-name
    Username: username
    Password: password

    See the "Connecting at Startup" section in "Remote Access to Progress/400 DataServer," for a description of the required and optional connection parameters.

    This connection information is stored with the schema holder. Progress uses the parameters that you provide here whenever you connect to the schema holder though the Data Dictionary or Data Administration tool, or reference a file within the DB2/400 database.

  10. Choose OK. After the utility loads the data definitions of the P__ files, you can choose to synchronize the client schema holder with the server schema.
  11. Choose OK. A message appears when the synchronization is complete.
  12. Choose OK.

The Progress Data Administration tool provides a set of DB2/400 utilities that you can use to maintain a client schema holder. See "Remote Client DB2/400 Utilities," for descriptions of these utilities.

Deploying a Schema Holder

The guidelines and techniques that apply to deploying a Progress database also apply to deploying a schema holder for DB2/400 database files. However, you must make changes to both the supporting DB2/400 database files and the schema holder. There are two techniques for updating a schema holder:


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