You export metadata from the Data Warehouse Center if you want your partner application to operate on data sources or targets that are defined in the Data Warehouse Center.
Exporting metadata from the Data Warehouse Center involves the following procedures:
Most Data Warehouse Center objects are specific to the Data Warehouse Center. However, you can use metadata about databases, tables, and columns to define source and target databases for partner applications. You can use this capability to share source and target information between partner applications that transform data for the same warehouse.
For example, one partner tool might unload data from a database into a target file. Another partner tool might use the file as a source file and:
A third partner tool might read the data from the file and load it into a target database. If you export the metadata for the databases and files from the Data Warehouse Center, you can make sure that all the partner tools are using the same data definitions.
To define source databases, export one or more warehouse sources (all tables and columns are included automatically). To define a target database, export a warehouse target (all tables and columns are included automatically).
When you export the objects, the Data Warehouse Center writes the objects in a file, using tag language format. For information about the tags that are used to identify metadata for source databases and target databases, see Data Warehouse Center metadata. For the syntax and structure of a tag language file, see Tag language and What a tag language file should look like.
Table 12 shows the mapping between the logical Data Warehouse Center
objects and the tag language object that represents the logical object.
Table 12. Logical objects for source and target databases
| Data Warehouse Center logical object | Object in tag language file | Description | See: |
|---|---|---|---|
| Warehouse Source | DATABASE | Source database or file | DATABASE object |
| Warehouse Target | DATABASE | Target database or file | DATABASE object |
| Table | TABLES | Table, file, or segment in source or target database | TABLES object |
| Column | COLUMN | Column or field in table or field in file | COLUMN object |
You can use the Data Warehouse Center user interface or a command window to export metadata from the Data Warehouse Center. This section covers how to use the command window. For information about using the user interface, see the Data Warehouse Center online help and the Data Warehouse Center Administration Guide.
First, you create an .INP file with the list of warehouse sources and warehouse targets that you want to export. For example:
<IR> LOG_STAT_IR LOG_STAT_REP
LOG_STAT_IR is a warehouse source, and LOG_STAT_REP is a warehouse target. The Data Warehouse Center automatically exports the tables and columns that are associated with LOG_STAT_IR and LOG_STAT_REP.
Then, to export the tag language file, enter the following command at a DOS command prompt:
iwh2exp2 INPfilename controlDBname userid password [PREFIX = schema]
Create this file in a read/write directory because the Data Warehouse Center will write the tag language file in this directory. The Data Warehouse Center names the tag language file INPfilename.TAG.
If a prefix is not specified, the default value is IWH.
For more information about exporting metadata from the Data Warehouse Center, see the Data Warehouse Center Administration Guide.
The import formats and the export formats are release-dependent. You cannot use exported files from a previous release to migrate from one release of the Data Warehouse Center to another. For more information on migration, see the Quick Beginnings book for your platform.