Managing VSAM Metadata

In this section:

When the server accesses a data source, it interprets the data stored there based on instructions in a synonym that you create, which describes the structure of the data source and the server mapping of the VSAM data types.


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Creating Synonyms

How to:

Reference:

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Synonyms define unique names (or aliases) for each VSAM file or view that is accessible from the server. Synonyms are useful because they hide the underlying data source location and identity from client applications. They also provide support for extended metadata features of the server, such as virtual fields and additional security mechanisms.

Using synonyms allows an object to be moved or renamed while allowing client applications to continue functioning without modification. The only modification required is a redefinition of the synonym on the server. The result of creating a synonym is a Master File that represents the server metadata.



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Procedure: How to Create a Synonym

To create a synonym, you must have previously configured the adapter. You can create a synonym from the Applications or Adapters pages of the Web Console.

  1. From the Web Console menu bar, click Applications.

    The Applications page opens.

  2. Click the New button and select Synonym from the drop-down menu.

    The Select adapter to configure or Select connection to create synonym pane opens.

  3. Click a connection for the configured adapter.

    The first of a series of synonym creation panes opens.

  4. Enter values for the parameters required by the adapter as described in the synonym creation parameters reference.
  5. After entering the parameter values, click Create Synonym.

    The Status pane indicates that the synonym was created successfully.

The synonym is created and added under the specified application directory.

Note:



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Reference: Synonym Creation Parameters for VSAM

The following list describes the parameters for which you will need to supply values, and related tasks you will need to complete in order to create a synonym for the adapter. These options may appear on multiple panes. To advance from pane to pane, click the buttons provided, ending with the Create Synonym button, which generates the synonym based on your entries.

Select File System Option

Under File System Selection, choose one of the following options:

  • Fully qualified PDS name to indicate a partitioned dataset on MVS.

    In the input boxes provided, enter a PDS name preceded by a double slash (//) and a Member name containing the location of the COBOL FD source. If you wish, you can filter the member name using a wildcard character (%).

    or

  • Absolute HFS directory pathname to indicate a hierarchical file structure on USS.

    In the input boxes provided, type a Directory name to specify the HFS location that contains the COBOL FD and File name and File extension. If you wish, you can filter the file and extension using a wildcard character (%).

Click Submit

The Create Synonym pane (Step 2 of 2) opens.

If selected, the filtered COBOL definition is displayed at the top of the pane.

Enter the following parameters, as required:

Validate

Select the Validate check box if you wish to convert all special characters to underscores and perform a name check to prevent the use of reserved names. (This is accomplished by adding numbers to the names.) This parameter ensures that names adhere to specifications. See Validation for Special Characters and Reserved Words for more information.

When the Validate option is unchecked, only the following characters are converted to underscores: '-'; ' '; ' \'; '/'; ','; '$'. No checking is performed for names.

Make unique

Select the Make unique check box if you wish to set the scope for field and group names to the entire synonym. This ensures that no duplicate names are used, even in different segments of the synonym. When this option is unchecked, the scope is the segment.

Set COBOL FD translation options

Optionally, select Customize COBOL FD conversion options to customize how the COBOL FD is translated. If you do not select the check box, default translation settings are applied.

For more information, see Customization Options for COBOL File Descriptions.

Application

Select an application directory. The default value is baseapp.

Prefix/Suffix

If you have tables with identical table names, assign a prefix or a suffix to distinguish them. For example, if you have identically named human resources and payroll tables, assign the prefix HR to distinguish the synonyms for the human resources tables. Note that the resulting synonym name cannot exceed 64 characters.

If all tables and views have unique names, leave the prefix and suffix fields blank.

Extended data format attributes

This option provides data portability between servers by enabling processing of data loaded in different encoding systems.

xClick the Extended data format attributes check box to display the Codepage option.

In the input box provided, enter the code page of the stored data. Your entry is added to the Master File of the generated synonym.

Note: The code page you specify here must one for which you have requested a customized code page conversion table as part of your NLS configuration. If you have not already requested a conversion table for the designated code page, you can do so now. On the Web Console menu bar, click Workspace, then Configuration, and choose NLS under General settings. The NLS Configuration Wizard opens. Click Customize code page conversion tables and select the check box for the code page you wish to use. Click the Save and Restart button to implement your new setting.

Overwrite Existing Synonyms

To specify that this synonym should overwrite any earlier synonym with the same fully qualified name, select the Overwrite existing synonyms check box.

Note: The connected user must have operating system write privileges in order to recreate a synonym.

Create Synonym parameters

Default Synonym Name

This column displays the names that will be assigned to each synonym. To assign different names, replace the respective displayed values. You have these additional options:

  • To select all synonyms in the list, select the check box to the left of the Default Synonym Name column heading.
  • Enter a cluster name under Dataset Location to associate it with a particular metadata description. The cluster name is embedded in the Master File. If you do not enter the cluster name during the synonym creation process, you will have to add it dynamically at run time.
  • To select specific synonyms, select the corresponding check boxes.


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Reference: Managing Synonyms

Once you have created a synonym, you can right-click the synonym name in the Adapter navigation pane of either the Web Console or the Data Management Console to access the following options.

Option

Description

Open

Opens the Master File for viewing and editing using a graphical interface. If an Access file is used it will be also available.

Edit as Text

Enables you to view and manually edit the Master File synonym.

Note: To update the synonym, it is strongly recommended that you use the graphical interface provided by the Open option, rather than manually editing the Master File.

Edit Access File as Text

Enables you to view and manually edit the Access File synonym.

Note: This option is available only when an Access File is created as part of the synonym.

Sample Data

Retrieves up to 20 rows from the associated data source.

Data Profiling

Data Profiling provides the data characteristics for synonym columns.

Alphanumeric columns provide the count of distinct values, total count, maximum, minimum, average length, and number of nulls.

Numeric columns provide the count of distinct values, total count, maximum, minimum, average value, and number of nulls.

Refresh Synonym (if applicable)

Regenerates the synonym. Use this option if the underlying object has been altered.

Data Management

Followed by these options, if applicable:

Recreate DBMS Table. Recreates the data source table. You are asked to confirm this selection before the table is regenerated. (Note that the table will be dropped and recreated. During the process, data may be lost.)

Delete All Data. Deletes all existing data. You are asked to confirm this selection before the data is deleted.

Insert Sample Data. Inserts specified number of sample records, populating all fields with counter values.

Reorganize. Recreates the data source table preserving original data.

Note: This option is not available in the Web Console.

Impact Analysis

Generates reports on procedures, synonyms, and columns that provide information on the flows/stored procedures available on a particular server, and the synonyms and columns they use. These reports enable you to evaluate changes before they are made by showing which components will be affected. See the Server Administration for UNIX, Windows, OpenVMS, IBM i, and z/OS manual for details about Impact Analysis reports.

Copy

Copies the synonym to the clipboard.

Delete

Deletes the synonym. You are asked to confirm this selection before the synonym is deleted.

Cut

Deletes the synonym and places it on the clipboard.

Properties

Displays the properties of the synonym, including physical location, last modified date, description, and privileges.


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