1. Optimizing SQL Performance with BMC SQL Performance for DB2 Introduction and Technical Update
9/20/2018

2. SQL Performance The Business Problem
The most challenging problem in DB2 shops today
Direct impact on meeting service level objectives
Direct impact on cost of ownership for the IT organization
What makes it difficult?
Dynamic Application Workloads
More and more dynamic SQL coming from distributed connections
SQL coding quality and validation
Why is this an even bigger deal today?
IT Dynamics driving the problem
Trending toward more dynamic SQL = less control
Outsourced application development
Less staff
People and experience to handle what is a complex task
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©2005 BMC Software

3. Analyzing and Tuning Your SQL - Sources of Information
Atomic SQL
SQL Workload
Focus on individual SQL statements
Do they meet “best practice” coding standards
Do they use expected/accepted DB2 access paths
Do they deliver desired result set in acceptable time with acceptable resource consumption
Developed and tested in controlled environment
More predictive in nature
Focus on workload dynamics
How does concurrent execution affect response time/resource consumption
Does this SQL statement/program collide with other transactions
Real world unpredictability comes into play
More focus on measuring the workload and rapidly reacting
      
                                                                                                                                                                          
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©2005 BMC Software

4. SQL Performance for DB2 The BMC Solution
Solution Objectives
Control or eliminate poorly performing SQL code
SQL performance problems identified and solved quickly
Proactive identification of inefficient SQL
Solution Components
APPTUNE captures and analyzes SQL execution metrics
SQL Explorer is the SQL analysis tool that extends far beyond the DB2 Explain
Index Analysis Component provides specific features for effectively managing DB2 indexes
Common Explain available in solution and point products
SQL Performance
for DB2
Data Collector
APPTUNE
for DB2
SQL Explorer
for DB2
Index
Component
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©2005 BMC Software

5. SQL Performance for DB2 Solution Architecture
This diagram illustrates the APPTUNE products major components:
Data Collector
Online Reports
Batch Reports
Administration
The following slides describe each of the major components in more detail.

6. SQL Performance for DB2 Starting at the /top
Key points
DB2 subsystems across your enterprise on a single screen
DB2s with highest elapsed times bubble to the top (generally the best place to start)
Results can be sorted on different field on display (getpages or CPU for example) with simple command
Drilldowns aplenty
Numerous drilldowns will take you into detail organized to your interest
ASQEQRPW/P View a Report LINE 1 OF 7
Command ====> _______________________________________________ Scroll ===> CSR_
BMCSftwr.SQMCACTS SUBSYSTEM ANALYSIS (DATA) /27 14:36:58
Source : V52A-ACTIVE Intvl : 08/27 00:00 - UNLIMITED More: >
Actions: G-AppGrps R-Programs C-ConnID T-Detail A-Averages O-Object
P-Plans U-Users S-Stmts E-SQL Errors L-CorrID
Actions for SAP systems: V-Server N-Work Process Number I-Work Process ID
AppGrp: User: ConnID: Plan:
CorrID: Program: Stmt No:
SQL Total IN-SQL Time S
DB2 SSID MVS ID Calls Elapsed % CPU % Getpage Numb
+ DFH1 (8.1) SYSM K 01: % 00: %
+ DFG1 (7.1) SYSO : % 00: %
Poor performance at the subsystem level
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©2005 BMC Software

7. Which statement is using the most resources?
Key points
Top SQL statements in terms of total elapsed time sorted to top
Dynamic and Static SQL visible
Numerous drilldowns for additional detail
SQL
Text
Objects
Accessed
Top three statements are using 90% of the CPU S
“S” again to see the SQL text
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©2005 BMC Software

8. “X” will invoke the common Explain function
Here’s the SQL
Key points
Provides extensive SQL statement execution detail on elapsed time, getpage activity, BP usage, lock events and CPU consumption
You can launch directly into a full-function explain from the common Explain function
“X” will invoke the common Explain function X
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©2005 BMC Software

9. Let’s Explain the statement
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10. Which DB2 Objects Are Used by this Statement?
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11. APPTUNE for DB2 As a Troubleshooting Tool
Current transaction problem ?
Subsystem
Thread
Locking contention
Do you have Distributed Applications? Do you need to identify the transaction by Workstation?
Need a way to report on application SQL errors?
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©2005 BMC Software

12. APPTUNE for DB2 Active Threads Running …
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13. SQL Error Analysis report
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14. SQL Explorer for DB2 Explain function Online interactive tool Batch
See detail when you want to see it on statistics, predicates, access path, objects
Customize the layout of the data the way you want to see it
Get advice and tips from Explain rules
See visual comparison from editing SQL and re-explaining
See visual comparison of dynamic explain and BIND with EXPLAIN(YES)
Solution password enables Index Component analysis on cloned objects:
Add one or more indexes
Drop one of more indexes
Update statistics on one or more indexes
Batch
See summary and detail explain information for many packages, collection IDs, or plans.
Explain objects in batch and save to product history tables to be used in Compare
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©2005 BMC Software

15. BMC Common Explain A Little More Detail
Predicate Information
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©2005 BMC Software

16. SQL Explorer for DB2 Additional Functionality
Compare Access Paths from two points in time
Compares on SQL Text, not statement number
Sets return code 8 if access path got worse
Shows differences in statistics that were used at the time of the Explain
Mismatch Analysis
Reports mismatches in data type or length that can affect access paths
Now incorporated into Explain Predicate report
Impact Analysis
Find all statements affected by a schema change
DBRM/LOAD Library Compare
Find mismatches in timestamps between DBRM and LOAD before you promote to production to avoid -805 / -818 SQL errors.
Migrate Access Path Statistics
Copy PROD statistics to TEST to get a better picture of the access paths
Declarations Generator
Generates null indicator variables to help avoid coding errors
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©2005 BMC Software

17. SQL Performance for DB2 – Index Component
Collects predicate data
Number of times a column was specified in a predicate and in what manner (Indexable Equal, Indexable Range)
Collects I/O information for DB2 objects
Inactive tables and inactive indexes
DB2 catalog statistics for tables and indexes
SQL statements associated with a table
Collects index usage
Percentage of getpages from indexes
Provides What-if Index analysis on cloned objects
Add indexes
Drop indexes
Update statistics on indexes
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©2005 BMC Software

18. Data at statement level provide matrix of activity
SQL Performance for DB2 – Index Component Table Access by GETPAGE/STMT Ratio report
Data at statement level provide matrix of activity
Activity against Objects
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©2005 BMC Software

19. SQL Performance for DB2 – Index Component Table Access by GETPAGE/STMT Ratio report
Enter M for Crud Matrix on the CR_Individual table
This is the percentage of getpages from indexes
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©2005 BMC Software

20. SQL Performance for DB2 – Index Component Table CRUD Matrix report
Let’s look at the usage of this column in the workload captured
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©2005 BMC Software

21. SQL Performance for DB2 – Index Component Table CRUD Matrix report – Column Detail
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©2005 BMC Software

22. SQL Performance for DB2 – Index Component Drilldown to SQL Text
The “X” option will launch the BMC Common Explain feature
Common Explain is an integrated common component used by a number of BMC products
Now we’ll proceed to the Explain function
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©2005 BMC Software

23. BMC Common Explain What-if Index Analysis Using Cloning
Now let’s look at modeling a new index that could provide a better access path
Common Explain uses a cloning technique that creates new objects or modifies existing objects
Clones created in a BMC database so no DBD locks
Objects created with DEFINE NO
Objects not created till a dynamic explain is executed
Objects dropped upon exiting Explain
Index statistics can be modified
Index DDL can be saved or imported into the process
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©2005 BMC Software

24. BMC Common Explain What-if Analysis
We’ve created a new index in this step and modified the statistics so the optimizer will have enough information
We can also delete existing indexes (deleted from the clone only) or update statistics data for existing indexes as well
Here is the index we created in the
previous step
Remember the index hasn’t
actually been created yet
Next step we’ll using the XD (Dynamic
Explain) to create the clone
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©2005 BMC Software

25. BMC Common Explain What-if Analysis
With the new index the access path
changes dramatically
Meanwhile the cost of the statement
has gone down as well
DDL for creating this index can be
saved for later use
The new index has dramatically affected the access path and caused the Cost Rate for this statement to go down
More importantly, the access path went from a tablespace scan to a matching index access
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©2005 BMC Software

26. SQL Performance for DB2 3.3.00 Solution Update Generally Available November 9, 2006
9/20/2018

27. SQL Performance 3.3.00 Technical Overview Release Highlights
Reduce solution overhead
Data Collector CPU and storage overhead
Architectural changes mean overhead reductions
Index Component overhead reduction
Eliminate bind requirement
Streamline reporting to reduce/eliminate redundant reports
Deliver new filtering capabilities
Exception only reporting (XOR)
Increased number of collection keys
Increased flexibility in defining exceptions and reducing overhead
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©2005 BMC Software

28. SQL Performance for DB2 3.3 Filtering Enhancements
Extensive work on current filtering capabilities to:
Deliver more filtering functionality
Make filtering easier to use
Enable new XOR option
Discussed later
Functional enhancements
Exceptions on GETPAGES, SQL Codes, Timeout/Deadlock Occurrences, Synchronous I/O Counts
In addition to existing exceptions (Elapsed and CPU times)
Ignore the literal in dynamic SQL statements where the rest of the statement is the same
Treats SQL statement as a single statement
New collection keys
Change collection items without cycling Data Collector (through filters)
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©2005 BMC Software

29. New Collection Options Panel
Simple means to turn off collection for
qualifiers
New collection keys
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©2005 BMC Software

30. New Collection Options Exception only roll-ups
Resource saving options specified as part
of individual filter so they can be applied to
specific portions of the workload
Combined with other collection options to
create a tailored profile for applications
Triggers exception only reporting
Idea is to minimize collection overhead
for stable applications with minimal
monitoring requirements
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©2005 BMC Software

31. New Collection Options Identifying Exception Criteria
Specifies exceptions on Elapsed and CPU
time, Negative SQL code, Deadlocks and
Timeouts, and synchronous I/O Counts
Exception records will be cut for each of
the exceptions that occur
Specifies collection of host variable values
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©2005 BMC Software

32. New Collection Options Filter Profile Definition for Legacy Applications
Exception-only reporting (XOR) specified
for programs (ACCT*) and plan (KAD4050)
No collection at all for payroll program -
PAYR650
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©2005 BMC Software

33. New Collection/Filtering Options Identifying Filters in Place for a Specific Interval
Allows user to identify collection/filtering options
in place during a specific interval
Based on current profile
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©2005 BMC Software

34. New Collection/Filtering Options Details on Active Filters
Collection options in place at time of interval
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©2005 BMC Software

35. New Collection/Filtering Options Drilling Into Exceptions
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©2005 BMC Software

36. New Collection/Filtering Options Exception Analysis
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37. Exception Analysis Exception Detail
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©2005 BMC Software

38. Exception Analysis Exception Detail w/Host Variables
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©2005 BMC Software

39. Additional SQL Performance Enhancements
Improvements in reporting on Query Parallelism
PSSBLOAD – Utility for loading APPTUNE performance data to DB2 tables for analysis
PSSEXTRC – Explain and compare dynamic SQL access paths across time or DB2 releases
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©2005 BMC Software

40. PSSBLOAD: Loading APPTUNE data into DB2 Tables
Load performance data into DB2 for analysis
Historical performance trends—You might want to know which SQL statements had the highest CPU in a given month, or which statement had the highest number of executions during a batch window.
Audit database—You might want to know which users accessed a particular table, or which users tried to access unauthorized tables.
Impact Analysis—You might want to identify the programs, statement numbers, and SQL text that accessed a particular table.
How’s it work
Reads archived trace data sets containing SQL performance data
Extracts the BMC IFCID data from the archives
SQL Text
SQL Errors (SQLCA)
SQL Statement Summary
Object Statistics (per statement)
Creates output data sets used for loading into DB2 tables
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©2005 BMC Software

41. Summary SQL Performance for DB2 3.3 available November 9th
APPTUNE 5.3
SQL Explorer for DB2 5.3
Significant reduction in Data Collector overhead
For APPTUNE and Index Component
New functionality in managing collection keys and filters
Continued investment in BMC’s DB2 solutions
Continued focus on things that differentiate BMC
World class support
Innovative technology that solves critical business issues
Strong financial condition
9/20/2018
©2005 BMC Software