The Return of
The DB2 Top Ten Lists
Craig S. Mullins
craig.mullins@softwareonz.com
craig@CraigSMullins.com
©2010
SoftwareOnZ
©2010
SoftwareOnZ
The Top Ten Lists
And now, from the home office in
Sugar Land, Texas… a series of
DB2 Top Ten lists about various
topics ranging across the
following subjects:
• Performance
• Coding
• Design
• Administration
• Management
• Features
• Tools
©2010
SoftwareOnZ
©2010
SoftwareOnZ
The Ten Database Management Commandments
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Thou shalt always design databases from a logical data model.
Thou shalt always document thy database design.
(There are many important aspects of database administration,
but of them all,) data integrity shalt always remain the most important.
Thou shalt encrypt personal and sensitive information, both at rest and in transit.
Thou shalt implement appropriate security within thy database and between thy
DBMS and thy operating systems.
Thou shalt always maintain the recoverability of thy databases with sufficient
backups to meet the availability requirements of the business supported by the data.
Thou shalt implement a consistent and documented workflow process for
implementing database change that assures data integrity while minimizing
downtime.
Thou shalt always consider transaction performance and data availability in thy
database design.
Thou shalt also work with application developers to ensure efficient code is written
to access thy databases.
Thou shalt not download thy database to thy laptop.
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 Database Design Guidelines
1.
2.
3.
Always start with a logical data model
Follow relational database design rules - normalization
Create and follow consistent naming standards for all DB2
objects (including columns)
4. Favor declarative referential integrity (RI)
5. Don’t forget the free space
6. Always fully document the database design including all
implementation decisions
7. Plan for data purging and archiving
8. Design for sharing data… instead of copying it all over the
place!
9. Plan for performance (or availability) at design time
10. Plan for backup and recovery before implementation
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Benefits of Using DB2 CDC for DW/ETL
1.
Why move all of your data every night when just a fraction of the data actually changed?
2.
Near-real-time data delivery vs. daily extracts
- downstream users have access to most current information
3.
Significant reduction in CPU cycles by eliminating costly ETL processes
4.
Identify certain business events as soon as they occur
(i.e. claim submitted over $1M)
5.
High availability with active/active replication between data centers
6.
Optimize existing ETL processes by supplying only the data that has changed
7.
Real-time integration with newer applications
(i.e. send a text message if account balance goes negative)
8.
No need to modify existing applications to track data changes or publish specific
business events
9.
Extend the life of your legacy DB2 applications by integrating data changes with newer
applications
10.
Allows for auditing by tracking all data changes to important tables
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Development Best Practices
1.
2.
3.
4.
5.
6.
7.
8.
9.
Minimize network calls
Minimize passes through the data
Put the work into the SQL, not the program
Unlearn the “flat file” mentality
Be sure data type and length match in predicates
Know your Stage 1, Stage 2, and Indexable predicates
Document your code
Always check the SQLCODE or SQLSTATE
Analyze your access paths
(and tune your SQL in test)
10. Avoid Bachelor Programming Syndrome
©2010
SoftwareOnZ
©2010
SoftwareOnZ
*
SELECT C.color
FROM
Colors AS C
WHERE C.color NOT IN (SELECT P.color
FROM Products AS P);
Top Ten Common SQL Mistakes
1.
2.
3.
Assuming an ORDER BY is not necessary for ordered results
Forgetting the NULL indicator
Incorrect expectations when using the NOT IN predicate with
NULLs*
4. Coding predicates appropriately in Outer Joins
5. Not coding a cursor for a multi-row result
6. Recompiling but not rebinding
7. Forgetting to use single quotes around strings (instead of double
quotes)
8. Trying to modify a Primary Key column
9. Forcing dynamic SQL into static SQL (sometimes hundreds of
static SQL statements)
10. Asking for more data than you need (columns and/or rows)
Sometimes (erroneously) referred to as the SELECT * problem
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Compliance Concerns
1.
Data Quality
•
2.
3.
Data Retention
Database Security
•
•
•
•
4.
5.
6.
Authentication (Who is it?)
Authorization (Who can do it?)
Encryption (Who can see it?)
Audit (Who did it?)
Data Masking and Obfuscation
Database and Data Access Auditing
DBA Procedures (e.g. change management)
•
7.
8.
9.
10.
“Poor data quality costs the typical company at least ten percent (10%)
of revenue; twenty percent (20%) is probably a better estimate.”
“Unauthorized change is one of the best (and worst) ways to get your
auditor’s attention.”
Data Movement Tracking
Master Data Management
Data Definition and Categorization
Metadata Management
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Biggest Data Breaches
http://www.privacyrights.org/ar/ChronDataBreaches.htm
1.
2.
3.
4.
5.
6.
7.
8.
9.
Jan. 20, 2009 Heartland Payment Systems ~130 million
Oct. 2, 2009 U.S. Military Veterans 76 million
Jan. 17, 2007 TJ stores (TJX) 45.7 million
June 16, 2005 CardSystems over 40 million
Dec. 15, 2009 RockYou 32 million (SQL injection)
May 22, 2006 U.S. Dept. of Veteran's Affairs 28.6 million
Mar. 8, 2006 iBill 17,781,462
Mar. 26, 2008 Bank of New York Mellon 12.5 million
July 3, 2007 Fidelity National Information Services (Certegy
Check Services Inc.) 8.5 million
10. Sept. 14, 2007 TD Ameritrade Holding Corp. 6.3 million
As of Feb 17, 2010, total records breached: 345,724,373 (since January 2005)
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Non-Technical Security Steps
1.
2.
3.
4.
5.
6.
7.
8.
Buy and use a good shredder
Don’t wear your ID badge outside of the office
Be vigilant when using your laptop in public
Buy and use a screen “shade”
Don’t put identification on your laptop (e.g. ID tags)
Company should invest in an anonymous PO box
Be careful about company logo clothing
Don’t leave unencrypted disks/USB sticks/etc. laying
around
9. Invest in a laptop lock and use it whenever possible
10. Never put any disk you do not know into your
computer (salaries)
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Under-Utilized Features
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Table Expressions
CASE statements
REOPT (other than NONE)
Triggers
Auto expand buffer pools
Real Time Stats
User-Defined Functions
DISTINCT Types
LOBs
Date/Time Arithmetic
XML?
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Specialty Processor Workloads
IFL: Linux “stuff”
zIIP: distributed SQL requests
zIIP: parallel SQL requests
zIIP: data warehousing/star schema
zIIP: native SQL stored procedures run via DDF (V9)
zIIP: index maintenance during LOAD, REORG, and
REBUILD
7. zAAP: Java
8. zAAP: XML
9. (zAAP on) zIIP: Java and XML
10. zIIP: non-DB2 stuff including:
1.
2.
3.
4.
5.
6.
•
z/OS Communcation Server encryption, z/OS XML System Services, and System Data
Mover processing associated with zGM/XRC (z/OS Global Mirror)
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten A-Ha! Moments
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Changing the SQL terminator for triggers
Truly understanding locking
When you can predict access paths by looking at SQL (and
statistics)
Being a human compiler (or JCL checker)
When your first reaction is to look it up in the manual instead of
asking the DBA
When you take responsibility for your professional development
When you start thinking about the business problems your
programs and database solve before thinking about a “neat”
technical issue
When you stop thinking of fetching from a cursor like reading from
a file
When you stop blaming DB2 before your own code
When you look at this list and say “that all makes sense”
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 Myths
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Use Views to Insulate Programs from Change
Locking Problems Indicate a Database Problem
Primary Key is Usually a Good Choice for Clustering
Just Using the Defaults Should Work Out Well
Programmers Don’t Need to Know How to Tune SQL
Black Boxes Work Well for Performance
Using NULLs Can Save Space
RUNSTATS Aren’t That Important
DB2 is a Hog
It Depends!
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Outdated Standards
Limiting indexes per table to 3… or 5… or…
Requring base table views
Forbidding dynamic SQL
Limiting number of tables per join (typically for online
txns)
5. Avoiding NULLs
6. Arcane table naming standards (e.g. TXR0031)
7. Just about any buffer pool standard (e.g. BP0 only)
8. Almost any standard using the words “always” or
“never”
9. GRANT…WITH GRANT OPTION
10. Putting standards in a binder instead of online
1.
2.
3.
4.
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Things to Do Before You Visit the DBA
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Try to Figure It Out Yourself, Please
RTFM
Figure out what you are going to say to him/her
Be sure it is the truth!
Don’t assume you (or your code) are innocent
Have a drink (coffee?)
Bring the DBA a drink (your choice!)
Never say “But IBM said it should work this way.”
Never say “But it worked that way yesterday.”
Always say “Thank you.”
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Ten Eleven Rules of the Road for DBAs
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Write Down Everything
Keep Everything
Automate
Share Your Knowledge
Focus Your Efforts
Don’t Panic!
Measure Twice, Cut Once
Understand the Business
Don’t Be a Hermit
Use All of the Resources at Your Disposal
Keep Up-to-Date
From zJournal article available at: http://www.craigsmullins.com/zjdp_042.htm
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Weasel-Speak Interpretations (Part 1)
1.
We will look into it
(We will forget all about it the moment you leave)
2.
It is in process
(The bureaucracy involved has rendered it hopeless)
3.
I didn’t get your e-mail
(I was too busy updating my Facebook status to read
your e-mail)
4.
The entire project is being abandoned [or reorganized]
(The only guy who understood it just left or retired)
5.
A number of different approaches are being tried
(We are all just guessing at this point)
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Weasel-Speak Interpretations (Part 2)
6. Preliminary tests were inconclusive
(We can’t get the dang thing to run)
7. Test results are very promising
(Amazing, it actually works)
8. What do you think about this…
(I only want your opinion so you can share the blame
later)
9. Robust
(We want you to buy this thing but have no Earthly idea
how to convince you, so we call it robust)*
10. Low maintenance
(Almost impossible to fix)
* See also, “Best of Breed”
©2010
SoftwareOnZ
©2010
SoftwareOnZ
http://www.redbooks.ibm.com/
Top Ten, err, Twelve DB2-Related
•
•
SG24-7330 DB2 9 for z/OS Technical Overview
SG24-6763 The Business Value of DB2
•
•
SG24-6300 DB2 for z/OS Application Programming Topics
SG24-6289 DB2 9 for z/OS: Using the Utilities Suite
•
•
•
SG24-7322 DB2 for z/OS: Data Sharing in a Nutshell
SG24-7720 Securing and Auditing Data on DB2 for z/OS
SG24-7688 DB2 9 for z/OS: Packages Revisited
•
•
SG24-7473 DB2 9 for z/OS Performance Topics
SG24-7134 DB2 UDB for z/OS: Design Guidelines for High Performance and Availability
•
•
•
SG24-7604 DB2 9 for z/OS Stored Procedures: Through the CALL and Beyond
SG24-7663 DB2 9 for z/OS: Deploying SOA Solutions
SG24-6319 DB2 for z/OS and WebSphere: The Perfect Couple
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 Twitter-ers
©2010
SoftwareOnZ
©2010
SoftwareOnZ
z/OS
LUW
Top Ten LUW vs. z/OS Differences
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Memory: EDM Pool, RID Pool, Sort Pool, Buffer Pools versus Catalog Cache,
Package Cache, Sort Heap, Buffer Pool, Locklist
Table Spaces: Simple (obsolete), Segmented, Partitioned, Universal (V9), LOB
versus Regular, Temporary, Large, Automatic (V9.5)
Optimizer: 7 levels of optimization in LUW (0,1,2,3,5,7,8)
Monitoring: Traces and Instrumentation Facility versus Event Monitor, Snapshot
Monitor
XML: XPath versus XPath, XQuery
Index Compression: z/OS only
Oracle syntax suport: LUW only
Multi-row INSERT, FETCH & multi-row cursor UPDATE: z/OS only
SET CURRENT ISOLATION: LUW only
Bottom Line: amazingly similar but different enough to make transitioning from
one to the other non-trivial
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 9 for z/OS
Application Developer Features
1.
2.
3.
4.
5.
6.
Plan Management: Package Stability
MERGE
SELECT FROM UPDATE, DELETE, & MERGE
Index on Expressions
Native SQL Procedure Language
FETCH FIRST and ORDER BY in subselect
and fullselect
7. INTERSECT and EXCEPT
8. INSTEAD OF TRIGGER
9. TRUNCATE
10. LOB Improvements
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 9 for z/OS DBA Features
1.
Universal Table Spaces
- PBG and range-partitioned
2.
3.
4.
5.
6.
Reordered Row Format
Index Compression
CLONE Tables
BUILD2 Phase Eliminated in Online REORG
APPEND YES
– ignoring clustering during INSERT and LOAD
7.
8.
9.
10.
The promise of REOPT(AUTO)
IMPLICITLY HIDDEN columns
New Data Types: BIGINT, DECFLOAT, BINARY/VARBINARY
Database Definition on Demand
- renaming a table’s column; renaming an index
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 10 Features
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
“…best reduction in CPU for transactions, queries, and batch since V2.1…
most customers to reduce CPU times between 5% and 10% as soon as
DB2 10 is out of the box.”
Improved Security
(e.g. data masking, smaller granularity for admin privileges)
Index Include Columns
Temporal (Versioned) Data
Hashing
Buffer Pool Improvements
(e.g.use of the System z10 1 megabyte, page size, buffer pools in
memory)
80% to 90% of Virtual Storage Moved “Above the Bar”
No More Links in the DB2 Catalog
Efficient Caching of Dynamic SQL Statements That Use Literals
LOB Improvements
(e.g. inline LOBS, improved large object streaming)
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Trends
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Industry Consolidation
Cloud Computing
SaaS
Virtualization
Server Consolidation
Open Source
Social Media
Complexity
Autonomic, Self-Managing Databases
Commoditization
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Best Practices
for DB2 Professional Development
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Join your local DB2 user group (and participate!)
Join IDUG and attend the annual conference in your geography
Lobby for relevant annual training
Purchase and read DB2 and database books
Subscribe to relevant magazines and read them regularly (e.g. IBM
Database Magazine, Database Trends & Applications, zJournal)
Subscribe to RSS feeds for DB2-related blogs (mine [DB2 Portal and
Data Technology Today], Willie Favero, Troy Coleman, Dave Beulke,
Robert Catterall, etc.)
Subscribe to the DB2 mailing list (daily DIGEST perhaps)
Visit IBM DeveloperWorks frequently
(http://www.ibm.com/developerworks/data/)
Download the DB2 manuals in PDF form
Be business savvy, not just tech savvy! Learn about your business.
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten DB2 Related Blogs
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Start with: Planet DB2 (DB2 blog aggregator) –
http://www.planetdb2.com
DB2 Portal Blog - http://www.db2portal.com/blog.html
Getting the Most Out of DB2 for z/OS (Willie Favero) http://it.toolbox.com/blogs/db2zos
DB2 News & Tips - http://db2news.blogspot.com/
DB2 USA - http://db2usa.blogspot.com/
Dave Beulke’s Blog - http://davebeulke.com/
DB2utor (Troy Coleman) http://ibmsystemsmag.blogs.com/db2utor/
Thoughts on DB2 (Triton) - http://www.triton.co.uk/blog/
SAP on DB2 for z/OS (Omer Brandeis) http://it.toolbox.com/blogs/sap-on-db2
Robert Catterrall - http://catterallconsulting.blogspot.com/
©2010
SoftwareOnZ
©2010
SoftwareOnZ
Top Ten Books for
DB2 Professionals
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
DB2 Developer’s Guide
©2010
SoftwareOnZ
©2010
SoftwareOnZ
The Return of the DB2 Top Ten Lists
Craig S. Mullins
craig@craigsmullins.com
http://www.CraigSMullins.com
craig.mullins@softwareonz.com
http://www.softwareonz.com
©2010
SoftwareOnZ
©2010
SoftwareOnZ