Managing Model 204 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 Model 204 data types.

The logical description of a Model 204 file is stored in a Master File, which describes the field layout. The physical attributes of the Model 204 file, such as the keys description, occurring data access, 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 Model 204 table 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 and Access File, which represent 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 Model 204

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.

File name

Is the Model 204 file name.

File password

Is the associated password for the file. This entry is optional.

Rectype name

Is a valid Model 204 field with the name RECTYPE. This entry is optional.

Rectype value

Is a valid value of the Model 204 field with the name RECTYPE. This entry is optional.

Synonym name

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

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.



Example: Creating a Synonym

To generate a synonym for the VEHICLES data source, enter the following information on the Create Synonym panes of the Web Console or the Data Management Console:

  1. On the first Create Synonym pane, enter VEHICLES in the File Name field and WHEELS in the File Password field.
  2. Enter m204veh as the Synonym name.
  3. Select m204 from the Application list.
  4. Click Create Synonym. The synonym is created and added under the specified application directory (baseapp is the default).
  5. The Create Synonym Status pane indicates that the synonym was created successfully. Click Applications on the menu bar.
  6. Open the baseapp application folder in the navigation pane and click the synonym m204.
  7. Choose Edit as Text from the menu to view (and edit) the generated Master File and Access File.

Generated Master File:

FILENAME=M204VEH, SUFFIX=M204INX , $
  SEGMENT=VEHICLES, SEGTYPE=S0, $
    FIELDNAME=BODY, ALIAS=BODY, USAGE=A4, ACTUAL=A4, $
    FIELDNAME=COLLISION_PREMIUM, ALIAS='COLLISION PREMIUM', USAGE=I9, ACTUAL=A9, $
    FIELDNAME=COLOR, ALIAS=COLOR, USAGE=A255, ACTUAL=A255, $
    FIELDNAME=DEDUCTIBLE, ALIAS=DEDUCTIBLE, USAGE=I9, ACTUAL=A3, $
    FIELDNAME=GARAGING_LOCATION, ALIAS='GARAGING LOCATION', USAGE=A4, ACTUAL=A4, $
    FIELDNAME=LIABILITY_LIMIT, ALIAS='LIABILITY LIMIT', USAGE=I9, ACTUAL=A3, $
    FIELDNAME=LIABILITY_PREMIUM, ALIAS='LIABILITY PREMIUM', USAGE=I9, ACTUAL=A9, $
    FIELDNAME=MAKE, ALIAS=MAKE, USAGE=A255, ACTUAL=A255, $
    FIELDNAME=MODEL, ALIAS=MODEL, USAGE=A255, ACTUAL=A255, $
    FIELDNAME=OTHER_DRIVER, ALIAS='OTHER DRIVER', USAGE=A255, ACTUAL=A255, $
    FIELDNAME=OWNER_POLICY, ALIAS='OWNER POLICY', USAGE=A6, ACTUAL=A6, $
    FIELDNAME=PRINCIPAL_DRIVER, ALIAS='PRINCIPAL DRIVER', USAGE=I9, ACTUAL=A9, $
    FIELDNAME=SURCHARGE%, ALIAS=SURCHARGE%, USAGE=A255, ACTUAL=A255, $
    FIELDNAME=TRANS, ALIAS=TRANS, USAGE=A2, ACTUAL=A2, $
    FIELDNAME=USAGE, ALIAS=USAGE, USAGE=A255, ACTUAL=A255, $
    FIELDNAME=VEHICLE_PREMIUM, ALIAS='VEHICLE PREMIUM', USAGE=I9, ACTUAL=A9, $
    FIELDNAME=VEHICLE_RATING, ALIAS='VEHICLE RATING', USAGE=A1, ACTUAL=A1, $
    FIELDNAME=VEHICLE_USE_CLASS, ALIAS='VEHICLE USE CLASS', USAGE=A2, ACTUAL=A2, $
    FIELDNAME=VIN, ALIAS=VIN, USAGE=A10, ACTUAL=A10, $
    FIELDNAME=YEAR, ALIAS=YEAR, USAGE=A255, ACTUAL=A255, $

Generated Access File:

 SEGNAM=VEHICLES, CONNECTION=M204, FILE=VEHICLES, PASS=WHEELS, $
  FIELD=BODY, TYPE=ORA, $
  FIELD=COLLISION_PREMIUM, TYPE=ORN, $
  FIELD=COLOR, TYPE=ORA, $
  FIELD=DEDUCTIBLE, TYPE=ORN, $
  FIELD=GARAGING_LOCATION, TYPE=ORA, $
  FIELD=LIABILITY_LIMIT, TYPE=ORN, $
  FIELD=LIABILITY_PREMIUM, TYPE=ORN, $
  FIELD=MAKE, TYPE=ORA, $
  FIELD=MODEL, TYPE=ORA, $
  FIELD=OTHER_DRIVER, TYPE=KEY, $
  FIELD=OWNER_POLICY, TYPE=ORA, $
  FIELD=PRINCIPAL_DRIVER, TYPE=ORN, $
  FIELD=TRANS, TYPE=ORA, $
  FIELD=USAGE, TYPE=ORA, $
  FIELD=VEHICLE_PREMIUM, TYPE=ORN, $
  FIELD=VEHICLE_RATING, TYPE=ORA, $
  FIELD=VEHICLE_USE_CLASS, TYPE=ORA, $
  FIELD=VIN, TYPE=ORA, $

M204 fields may have KEY and ORDERED attributes at the same time. In such cases, the field in the Access File has TYPE=KEY(IVK for invisible field) and a comment with information about another possible TYPE:

 SEGNAM=RNG, CONNECTION=M204, FILE=RNG, $
  FIELD=FKEY, TYPE=KEY, ATTRIBUTE=FRV, $
  FIELD=FORC, TYPE=KEY, $
$  Field has KEY and ORC attributes. KEY is chosen.      $
  FIELD=FORN, TYPE=KEY, $
$  Field has KEY and ORN attributes. KEY is chosen.      $
  FIELD=FRNG, TYPE=RNG, $


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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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