Background about !DB/EXPLAIN for DB2 | Candle-lite manual

Background about !DB/EXPLAIN for DB2

Background about !DB/EXPLAIN for DB2

This section provides an overview of the !DB/EXPLAIN functionality.

Functions provided by !DB/EXPLAIN for DB2

!DB/EXPLAIN provides a window into the operation of DB2. !DB/EXPLAIN offers benefits for

■extracting DB2 data

You can extract all or a portion of the data in the DB2 catalog according to the criteria you specify. This flexible technology lets you

–Extract and combine data from multiple PLAN_TABLES.

–Access data when DB2 is not active.

–Avoid contention on the DB2 catalog.

–Retain histories of plan, package, and DBRM catalog data and their EXPLAINs.

■DB2 database administration

You can use !DB/EXPLAIN functions to review and improve SQL. These features let you

–Review application code and monitor specific SQL performance to understand the access paths and their relative costs.

–Store historical information to perform impact analysis, historical analysis, and perform “what-if” analysis.

–Manage DB2 objects by viewing statement use by package or plan and DBRMs and BIND, REBIND, or FREE DB2 objects.

–Facilitate migration to a newer version of DB2.

■application development

You can use !DB/EXPLAIN to analyze your design and improve SQL. These features let you

–Analyze SQL code within an ISPF session to obtain access path information.

–Identify potential trouble spots.

–Execute SQL code within a batch facility and obtain a report.

–Obtain direct access from the IBM Query Management Facility (QMF) to different types of queries.

–Tune your SQL code efficiently by suggesting more efficient alternative techniques.

90 OMEGAMON II for DB2 User’s Guide: CUA Interface, Version 540

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Candle-lite manual Background about !DB/EXPLAIN for DB2, Functions provided by !DB/EXPLAIN for DB2

Contents

User’s Guide CUA Interface Omegamon II for DB2 User’s Guide CUA Interface, Version Contents Index 129 List of Figures Omegamon II for DB2 User’s Guide CUA Interface, Version Preface Who should read this book Where to look for informationAbout This Book Documentation set information Printing problems? Adobe Portable Document FormatIntroduction Documentation Conventions REPORT=SUMMARY Histogram Candle Customer Service and Satisfaction Candle Customer Service and Satisfaction contactsBackground Page Omegamon II for DB2 User’s Guide CUA Interface, Version Historical Reporter redesign New IFCID-based reports Unicode support Bit addressing supportLong name support Enclave support New Dsnzparm fields Distributed Thread display improvements Omegamon II for DB2 User’s Guide CUA Interface, Version Chapter Contents Introduction Logging on to the application Where applid is the application nameSigning On Sign On panel Fields of the Sign On Panel are defined in the table below Accessing Omegamon from OmegaviewSign On panel fields Field Description Setting Logon Options Logon Options panel fields Logical rows Number of logical rows Signing Off Returning to Omegaview from Omegamon Panel Features Panel featuresPart Feature Description Part Feature Description Highlighted data fields Data PanelsDescription Scrolling Pushbuttons Action Bar Selecting from the action barFast pathing from the action bar Actions pull-down GoTo pull-down View pull-down Options pull-down Tools pull-downHelp pull-down Available action codes Using an action codeAction Codes You can use these action codes in Omegamon Function key assignments Default function key assignments are listed belowFunction Keys Function Name Assignment Key Omegaview CUA/TSOPA1 PA2 Omegaview Help from the action bar Getting HelpHelp from a panel Help menu provides the following selections Using the Glossary Searching the glossaryIf you are Help function keys Customizing Omegamon Introduction To access the Preferences pop-up window Accessing the Preferences windowUsing the Preferences window Specifying Panel Preferences Action to occur Accessing the Terminal Options window Using the Terminal Options windowSpecifying Terminal Options Auto Values for SQL Description Process LevelManual Save Saving Terminal Options Saving for current sessionSaving to a profile Using the thresholds windows Setting ThresholdsAccessing the Thresholds window Follow these steps to change threshold values Saving threshold values Adding a user Accessing user authoritiesAssigning User Authorities Deleting a user Profile types Accessing profile maintenanceMaintaining Profiles Omegamon II uses three different profiles D61A$DEFAULT Copying a profile Deleting a profile Importing a ProfileExporting a Profile Modifying a profile description Switching profiles Using the Dynamic Profile Update Facility MVS Modify command for exporting a profile is as follows Example command for exporting a profileExample command for importing a profile MVS Modify command for importing a profile is as follows Using the Filter Options window Setting Filtering Options for Near-Term Thread HistoryAccessing the Filter Options window To access the Filter Options pop-up window Time Accessing the Save SQL Text Parameters window Using the Save SQL Text Parameters windowSpecifying Save Options for SQL Text Using the Callable Interface Set up the CUA options Set up the !DB/EXPLAIN options SQLID.PLANTABLE Setting Up !DB/EXPLAINSetting Up the CUA Options Step Action Log onto CUA Setting Up the D2/EXPLAIN Options Use the following procedure to set up the D2/EXPLAIN options Text and invokes the Explain function Use the following procedure to Explain SQL EXPLAINing SQL CodeAppend CPU % Press the Process SQL key Page Using Omegamon This chapter describes how to use Omegamon Monitoring from the System Status Panel DB2 subsystem componentsMonitored objects Investigating an alert Status indicatorsAlert notification Color Status Performing actions from the System Status panel System Status Components and Related Exceptions Cics exceptionsDescription Code Explanation Background exceptions IMS exceptionsTSO exceptions Utility exceptions Active thread exceptions Following exceptions apply to active threads Inactive thread exceptions Buffer pool exceptionsFollowing exceptions apply to buffer pool resources Log manager exceptions EDM pool exceptionsLock statistics exceptions DDF statistics exceptions Following exceptions apply to DB2 activity alerts DB2 activity exceptionsLock exceptions Following exceptions apply to lock alerts Volume activity exceptions Stored procedures exceptionsActive trace exceptions Following exceptions apply to alerts relating to triggers Triggers exceptionsUser-defined functions exceptions Following exceptions apply to user-defined functions Exception recommendations Investigating an Active Threads AlertActive threads alert Investigating the exception condition Evaluating and Modifying Thresholds Displaying all exceptionsModifying thresholds Adding or modifying rules Accessing near-term history data Reviewing Near-Term History DataThread activity for a reporting period Thread activity for a report interval Initiating a background application trace Specifying background application trace options Viewing the list of background traces Size Size of the dataset in megabytes VolumeIdentifying the dataset to which trace data is written Name of the dataset you want to create Activities you can perform in a background trace request Using the Ifcid Trace Facility OverviewStarting an Ifcid Trace Displaying Ifcid Trace Data Stopping an Ifcid Trace Page Using Omegamon II for DB2 Background about !DB/EXPLAIN for DB2 Functions provided by !DB/EXPLAIN for DB2 Using Omegamon II and !DB/EXPLAIN Complementary Functions When to use the complementary functionsAssumptions Using Omegamon II and !DB/EXPLAIN Complementary Functions Using the Omegamon II for DB2 Callable Interface Testc Current Sqlid is determined by the DB2 security exit Fields for Terminal Description Options SQL Text ATF. You can access the SQL Text panel through SAVE/EXPLAIN Required fields for the SAVE/EXPLAIN option Using the D2/EXPLAIN Options Panel PDS From the other !DB/EXPLAIN report sections that follow Press the Process SQL key Moving Interactively between !DB/EXPLAIN and Omegamon What functions can you use?Modes of operation Prerequisites for real time access Procedure to use the full function of !DB/EXPLAINWhat happens when you cancel the Omegamon II session? Using the Copy-and-Paste Facility in Omegamon Prerequisites to using the copy-and-paste facilityCapturing SQL from a running thread Capturing SQL using the ATF Prerequisites for using the Omegamon II trace information Accessing Omegamon II Trace Information from !DB/EXPLAINDirection of access Procedure to obtain current trace information Sources of information Task You Want to Perform Source of InformationPage Panel Navigation Flowcharts Appendix Contents Flowchart Conventions System Status panelElement Description System Status DB2 Workloads Panels Cics IMSTSO Workloads Panels Near-term history Cics IMS TSO Resources Panels Resources Panels Realtime Resources Panels Near-Term History Alerts Panels Alerts Panels Installation Parameters Panels Installation Parameters Panels Application Trace Facility Panels Application Trace Facility Panels Object Analysis Panels Object Analysis Panels Thread Detail GoTo Panels Thread Detail GoTo Panels Realtime Thread History Detail GoTo Panels Near-Term History Index Omegamon II for DB2 User’s Guide CUA Interface, Version 131 Omegamon II for DB2 User’s Guide CUA Interface, Version