4. Specify
the filter that you want to apply to this database connection by clearing the Disable
filter check box and building the filter for your database connection. For
our example, select the Selection radio button; select the schema you
used to create the SAMPLE database (in my case it was PAULZ because I was
logged onto a Windows system as this user and issued the db2sampl –xml –sql command);
select the Include selected items option from the corresponding
drop-down list. Then click Finish.
Filtering is a great idea when you
work with databases with large schemas. For example, some enterprise resource planning
(ERP) applications such as SAP or PeopleSoft can have over 30,000 tables! Filtering
provides a convenient way to quickly access only those schema objects you are
interested in. What’s more, it provides a security meta-data layer as well.
Generally, if you’re working with a large database schema, I strongly recommend
using a filter. Finally, your whole development environment will perform faster
because the entire schema won’t have to be fetched into the Database Explorer
view. As you can see in the previous figure, there are essentially two methods
you can use to build a filter: expressions and selections.
You can use the Expression filter
to define all sorts of variations of filters that are generated by almost any
imaginable sequence that relates to your schema names. The following figure shows
the different stemming options for an expression-based schema filter:
For this example, I just want the
tables in the PAULZ schema to show up in the Database Explorer view, so I
simply enter that into this field. When you use this approach to filter the
Database Explorer view you can end up with tables you didn’t expect t see. For
example, using the Starts with the characters option, the Database
Explorer view would include those tables within the PAULZ schema, but also
within any other schemas that start with these letters, such as PAULZ1 or
PAULZ2.
If you want to filter on a specific
schema (or schemas) and don’t require the advanced filtering generation
capabilities that the expression approach offers, you can simply select the Selection
radio button and select all the schemas you want included in the connection
object you are creating. For example, in the following figure, I’m defining a
filter on my database connection such that only those objects within the PAULZ
schema will appear in the Database Explorer view:
Note that you can include or
exclude objects on the basis of a schema name using the drop-down list within
the Selection box, as shown below:
As you can imagine, if you select Exclude
selected items from the drop-down list, all schema objects other
than those in the PAULZ schema will be shown in the Database Explorer view.
You can further filter objects
underneath a schema name once a connection is added to the Database Explorer
view. For example, assuming the previous filter (which included the PAULZ
schema) is applied to the database connection, you may want to filter those
tables further within the PAULZ schema to start with PROD such that only tables
like PRODUCT and PRODUCTSUPPLIER are shown within the PAULZ schema, as shown
below:
After you complete the previous steps, the Database Explorer view should now
look similar to the following figure:
You can see that a filter has been applied to the Schemas
folder. The [Filtered] keyword is added to any folder that is
filtered to give you design-time information in regards to why you may not see
the objects you are looking for. Of course, if you created a filter using the Exclude
selected items option detailed after Step 4, the Database Explorer view
would look like:
You can dynamically change a filter at any time by
right-clicking a filtered folder and selecting the Filter option.
Wrapping it up...
In this article, I introduced you to the Database Explorer
view that’s part of the new IBM DS DWB in the DB2 Viper II open beta. In
addition, I showed you how to add a database connection to this view and apply
filters to different schema objects to optimize the design-time experience for
your database. In the next article, I’ll introduce some of the tasks that you
can perform from the Database Explorer view.
»
See All Articles by Columnist Paul C. Zikopoulos
About the Author
Paul C. Zikopoulos, BA, MBA, is an
award-winning writer and speaker with the IBM Database Competitive Technology
team. He has more than 13 years of experience with DB2 and has written more
than 150 magazine articles and is currently working on book number 12. Paul has
authored the books Information on Demand: Introduction to DB2 9.5 New Features,
DB2 9 Database Administration Certification Guide and Reference (6th Edition),
DB2 9: New Features, Information on Demand: Introduction to DB2 9 New Features,
Off to the Races with Apache Derby, DB2 Version 8: The Official Guide, DB2: The
Complete Reference, DB2 Fundamentals Certification for Dummies, DB2 for
Dummies, and A DBA's Guide to Databases on Linux. Paul is a DB2 Certified
Advanced Technical Expert (DRDA and Cluster/EEE) and a DB2 Certified Solutions
Expert (Business Intelligence and Database Administration). In his spare time,
he enjoys all sorts of sporting activities, including running with his dog
Chachi, avoiding punches in his MMA class, and trying to figure out the world
according to Chloë – his daughter. You can reach him at: paulz_ibm@msn.com.
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Other company, product, or service names may be trademarks
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Copyright International Business Machines Corporation, 2007.
All rights reserved.
Disclaimer
The opinions, solutions, and advice in this article are from
the author’s experiences and are not intended to represent official
communication from IBM or an endorsement of any products listed within. Neither
the author nor IBM is liable for any of the contents in this article. The
accuracy of the information in this article is based on the author’s knowledge
at the time of writing.
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