Migrating from Test to Production › General Methods › Using the DISPLAY statement

Using the DISPLAY statement

Use for Small Volumes of Data

The DISPLAY statement of the schema, subschema, and DDDL compilers, and command facility is useful for moving small volumes of information between dictionaries under the control of the same DC/UCF system. Because this technique occurs online, system resources, such as response time and storage pool space, will limit the volume you are able to migrate.

Steps

There are four steps in the technique:

1. Sign on to the dictionary containing the components (the source dictionary)
2. Display the individual components using the AS SYNTAX clause.

   This step accomplishes the task of decompiling the components to a temporary work file. If you need to modify existing components in the target dictionary, use the VERB MODIFY option of the DISPLAY statement (DISPLAY ADD is the default action):

   display subschema empss01 as syntax verb mod.
   

3. While the components are in the compiler's work file, insert a SIGNON statement for the target dictionary into the work file as the first statement.

   This step prepares for the task of compiling the components from the temporary work file into the target dictionary. At the conclusion of this step, the work file contains a SIGNON statement for the target dictionary, followed by ADD or MODIFY statements for those components you want to migrate.

   Note: Typically the output of the previous step includes an echo of the input, so the first statement in the output is the DISPLAY statement. The DISPLAY statement is not necessary, so you can replace it with the SIGNON statement.

4. Invoke the compiler

   The compiler signs you off the source dictionary, signs you on to the target dictionary, and adds or modifies the components in the work file.

Final Tasks for Schemas and Load Modules

This technique will copy the source to the target dictionary, but it does not automatically validate schemas or recompile load modules for subschemas and edit and code tables. You can perform these additional functions in one of two ways:

• After you compile the source into the target dictionary, establish currency on the appropriate component and issue the VALIDATE or GENERATE statement. To establish currency, issue a simple MODIFY statement for the component. For example:

  modify subschema empss01.
  generate.
  

• Before you compile the source into the target dictionary, edit the work file by inserting the VALIDATE or GENERATE statement after the source for the component.