Managing MQSeries 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 MQSeries data types.

For the Adapter for MQSeries to access MQSeries files, you must describe each file you use in a Master and Access File. The logical description of an MQSeries file is stored in a Master File, which describes the field layout.


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Creating Synonyms

How to:

Reference:

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Synonyms define unique names (or aliases) for each MQSeries data structure that is accessible from a server. Synonyms are useful because they hide location information and the identity of the underlying data source 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 enabling 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.



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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 MQSeries

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.

QMGR

In the QMGR input field, enter the name of the queue manager on the machine where the server resides.

QUEUE

In the QUEUE input field, enter the message queue.

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 messages

To select all messages in the queue, click the check box to the left of the Default Synonym Name column heading.

To select specific messages in the queue, click the corresponding check boxes.

Default Synonym Name

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



Example: Creating a Synonym

To generate the following synonym for the variable mqpro from the Web Console or the Data Management Console:

  1. In the QMGR input field, enter edarisc64 as the name of the queue manager on the machine where the server resides.
  2. In the QUEUE input field, enter MQHOLD1 as the message queue.
  3. Click Select Operations.
  4. On the second Create Synonym pane, choose 41423 from the list of messages in the queue, 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

  5. From the message window, click Applications on the menu bar.
  6. Open the baseapp application folder in the navigation pane and click the synonym 41423.
  7. Choose Edit as Text from the menu to view the generated Master File. Your entries are reflected in the DATASET field.

    Generated Master File

    FILE     =MQPRO,
    SUFFIX   =MQS,
    DATASET  ="edarisc64"."MQHOLD1".
     414230000000000000000000000000000000000000000000, $
    SEGNAME  =MQPRO   ,
    SEGTYPE  =S0
    FIELDNAME=DIVISION4       ,E01         ,I11      ,I04     ,$
    FIELDNAME=DIVISION_NA4    ,E02         ,A25      ,A28     ,
    MISSING  =ON, $
    FIELDNAME=DIVISION_HE4    ,E03         ,I11      ,I04     ,
    MISSING  =ON, $
    $FIELD   =MSGID,
    $ ALIAS  =414230000000000000000000000000000000000000000000,
    USAGE    =A48,A48,$
    $FIELD   =CORID,
    $ ALIAS  =4942495F434F525F49443200000000000000000000000000,
    USAGE    =A48,A48,$
    $FIELD   =TIMEOUT,
    ALIAS    =0,
    USAGE    =I4,I4,$

Note: An Access File is not generated when you create a synonym from an MQSeries queue.



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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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Retrieving Foreign Messages From the Queue

You may receive the following types of messages:



Example: Retrieving Foreign Messages From the Queue

The Master File must be created manually. For example:

FILE=MQS1, SUFFIX=MQS,$
DATASET=edarisc3.MQHOLD1.41423, $
SEGNAME=ROOT, SEGTYPE=S0,$
FIELD=MESSAGE,     ALIAS=AA, USAGE=A720, A720 ,$
  GROUP=SPECIALS,  ALIAS=,   USAGE=A100, A100 ,$
    FIELD=MSGID    ALIAS=,   USAGE=A48,  A48  ,$
    FIELD=CORID,   ALIAS=,   USAGE=A48,  A48  ,$
    FIELD=TIMEOUT, ALIAS=0,  USAGE=I4,   I4   ,$

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Data Type Support

Data types in foreign messages are generated by application programs writing to the queues. If a COBOL copy book describing data layout exists, the metadata type could be generated by COBOL FD Translator.

The following chart provides information about the default mapping of MQSeries data types to server data types:

COBOL Format

Data Type

ACTUAL

USAGE

PICTURE X(n)

An

An

PICTURE 9(n)

Zn (packed option)

Pn (packed option)

PICTURE 9(n)

An (packed option)

Pn (packed option)

PICTURE S9(n)

Zn

Pn+1

PICTURE 9(n)V9(m)

Zn+m

Pn+m+1.m

PICTURE S9(n)V9(m)

Zn+m

Pn+m+2.m

PICTURE 9(n) COMP (1 < = n < = 4)

I2

I9

PICTURE 9(n) COMP (5 < = n < = 9)

I4

I9

PICTURE 9(n) COMP (n > 9)

A8

A8

COMP-1

F4

F8

COMP-2

D8

D15

PICTURE 9(n) COMP-3

P(n+2/2)

Pn

PICTURE S9(n) COMP-3

P(n+2/2)

Pn+1

PICTURE 9(n) V9(m) COMP-3

P(n+m+2/2)

Pn+m+1.m

PICTURE S9(n) V9(m) COMP-3

P(n+m+2/2)

Pn+m+2.m

The format conversions are subject to the following limitations:

The maximum length of the packed USAGE format depends on the software release that uses the generated Master File. For releases that support long packed fields (16 or more digits), the maximum ACTUAL length is 16 bytes and the maximum USAGE length is 31 digits (or 32 characters including a decimal point and sign). For earlier releases, the maximum ACTUAL length is 8 bytes and the maximum USAGE length is 15 total digits, including decimal and sign. The number of decimal places is limited to one fewer than the total USAGE length. In general, the USAGE length of packed fields is calculated as the sum of the digits to the left of the decimal (n), the number of decimal positions (m), one for the leading minus sign if present (S), and one for the decimal (V) if present.

The ACTUAL and USAGE formats for GROUP fields are always alphanumeric (A). The ACTUAL length is the sum of the ACTUAL lengths of its components. The USAGE length is the sum of the following:


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