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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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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.
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.
The Applications page opens.
The Select adapter to configure or Select connection to create synonym pane opens.
The first of a series of synonym creation panes opens.
The Status pane indicates that the synonym was created successfully.
The synonym is created and added under the specified application directory.
Note:
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.
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.)
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.
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.
Click this check box to use descriptive text from title fields as more meaningful field names in the synonym.
Select an application directory. The default value is baseapp.
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.
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.
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.
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.
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:
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
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, $
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. Drop Table. Drops the table so that it is removed from the DBMS. Insert Sample Data. Inserts specified number of sample records, populating all fields with counter values. Show/Modify Data. Opens a window that shows the data in the data source with buttons you can click to insert values, filter values, reload the data source, and customize the view. Reorganize. Recreates the data source table preserving original data. Note: This option is not available in the Web Console. |
Impact Analysis |
Generates a report showing where this synonym is stored and used, with links to the synonym instances. Impact Analysis reports enable you to evaluate changes before they are made by showing which components will be affected. See the Server Administration manual for details about Impact Analysis reports. |
Dependencies Analysis |
Generates a report showing information about the synonym and other synonyms and objects that are referenced within it. |
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. |
Privileges |
Shows the security subjects on the server and the privileges they have to this synonym. |
Properties |
Displays the properties of the synonym, including physical location, last modified date, description, and privileges. |
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