Managing DB Heritage Files Metadata

In this section:

When the server accesses a data source, it needs to know 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 DB Heritage Files data types.


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Creating Synonyms

How to:

Reference:

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Synonyms define unique names (or aliases) for each DB Heritage Files 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.

Note: Refer to Standard Master File Attributes for a DB Heritage Files Data Source, if you wish to review general information about Master File attributes, create a synonym based on attributes other than a standard DDS data definition, or make manual adjustments to synonyms generated using graphical tools.



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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 DB Heritage Files

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 Files

Choose the type of file you wish to see from the following options: All, Physical, or Logical. (At this level, there is no differentiation between logical and multi-format logical.)

Library Name

Supply the name of the library in which the physical and/or logical files reside. (Wildcards are not permitted.)

Note: When you create a synonym for DB Heritage Files on the IBM i platform, standard IBM i naming conventions apply to the target data source. Therefore, the Adapter for DB Heritage Files supports the use of double-quotation marks around any library name and/or file name that contains lower case or NLS characters.

Filter by Name

If you wish to limit retrieval, enter a full file name or a partial name with a wildcard symbol % in the Filter by Name input box. A full name returns just that entry. A name with a wildcard symbol may return many entries.

Use text description as field name

Click this check box to use descriptive text from title fields as more meaningful field names in the synonym.

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 objects for synonym creation

To select all member names in the list, select the check box to the left of the Default Synonym Name column heading. (If the library contains a large number of files, this check box will not appear, however, synonyms will be created for all files automatically.)

To select specific member names, click the corresponding check boxes.

Not all listed objects are data-related. Be sure to select those that are appropriate for creating synonyms.

Note: Mixed-case names or names with NLS character will appear in double quotation marks. However, the double quotation marks will be replaced by underscore characters in the Default Synonym Name column.

Default Synonym Name

This column displays the name that will be assigned to each synonym. To assign a different name, replace the displayed value.

Note: If you see a synonym name surrounded by underscore characters (as described in the previous note), you can remove the underscores if you wish.



Example: Creating a Synonym for a DB Heritage Files Data Source

In this example, the field attributes from the original file initialization are used in the new metadata. (For related information about file initialization, see Standard Master File Attributes for a DB Heritage Files Data Source.

An internal field (RECFORM) is also automatically added to reference a particular record's format. The RECFORM ALIAS always has a value of the name of the record format and is always added (even for single format files).

To generate the following synonym from the Create Synonym panes:

  1. Specify SHIPPING in the Library Name field, then click Submit.
  2. On the second Create Synonym pane, choose the member name DBF2901 from the list of objects that comprise the library and click Create Synonym.

    The synonym is created and added under the specified application directory (baseapp is the default).

    A status window displays the message: All Synonyms Created Successfully

  3. From the message window, click Applications on the menu bar.
  4. Open the baseapp application folder in the navigation pane and right-click the synonym DBF2901.
  5. Select Edit as Text from the drop-down menu to view the generated Master File. Your selections are reflected in the DATASET field, prefixed with QSYS:

    Generated Master File:

    FILENAME=DBF2901, SUFFIX=DBFILE  ,
     DATASET=QSYS:SHIPPING/DBF2901, $
      SEGMENT=DBF2901, SEGTYPE=S0, $
        FIELDNAME=CCODE1, ALIAS=COUNTRY_COD1, USAGE=A5, ACTUAL=A5,
          TITLE='COUNTRY_COD1', DESCRIPTION='Country Code Number 1', $
        FIELDNAME=CNAME1, ALIAS=COUNTRY_NAM1, USAGE=P16, ACTUAL=P8,
          TITLE='COUNTRY_NAM1', DESCRIPTION='Country Name Number 1', $
        FIELDNAME=RECFORM, ALIAS=DBF2901, USAGE=A10, ACTUAL=A10, $


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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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