Managing DATACOM Metadata

In this section:

When the server accesses a data source, it needs information on how to interpret the data stored there. For each data source the server will access, you create a synonym that describes the structure of the data source and the server mapping of the DATACOM data types.

For the Adapter for DATACOM to access DATACOM files, you must describe each file you use in a Master and Access File. The logical description of an DATACOM file is stored in a Master File, which describes the field layout. The physical attributes of the DATACOM file, such as the database number and security are stored in the Access File.


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Creating Synonyms

How to:

Reference:

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Synonyms define unique names (or aliases) for each DATACOM table or view that is accessible from the server. Synonyms are useful because they hide the underlying data source's 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 and Access File, which represent the server's 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 DATACOM

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.

Filter Data Base Name

The first Create Synonym pane displays the connection name, user table, and data dictionary ID that were supplied during configuration. To see all related databases, simply click Next.

If you wish to filter the list of available databases, click the Filter Data Base check box. A Name input box is added to the pane.

Type a string for filtering the list of databases, inserting the wildcard character (%) as needed at the beginning and/or end of the string, then click Next.

For example, enter: ABC% to select all databases whose names begin with the letters ABC; %ABC to select databases whose names end with the letters ABC; %ABC% to select databases whose names contain the letters ABC at the beginning, middle, or end.

Data Base Name

On the second Create Synonym pane, select a database from the drop-down list and click Next.

Filter Table Name

If you wish to filter the list of available tables, click the Filter Table Name check box. A Name input box is added to the pane.

Type a string for filtering the list of tables, inserting the wildcard character (%) as needed at the beginning and/or end of the string, then click Next.

Table Name

On the third Create Synonym pane, select a table in the selected database from the drop-down list and click Next.

URT or Connection

On the final Create Synonym pane, indicate whether you want to generate the synonym with a user requirements table (URT) or a connection name. The generated Access File Attributes depend on the method you choose here. (For an illustration of the differences, see Access Files Generated by URT and Connection.)

If you choose URT, enter the name of a user requirements table. This table defines the database and files that a user can access.

Note that this entry is not required for creating a synonym, however, data cannot be accessed without it. For more information about the user requirements table, see Controlling Data Access With a User Requirements Table.

If you choose Connection, enter the name of the connection that defines the URT and Database ID for accessing Datacom data.

Synonym name

Displays the name that will be assigned to the synonyms. To assign a different name, replace the displayed value.

Select 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.

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.

Select elements

An element is the smallest unit of data. An element contains fields that can belong to more than one element.

  • To select all elements in the list, select the check box to the left of the Element Name column heading.
  • To select specific elements, 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

Edit

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 Edit 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.

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 clipboard.

Delete

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

Cut

Deletes the synonym and places it in clipboard.

Properties

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


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