Generating Performance Profiles

You can generate the Performance Profile in any of the following ways:

From Option 4 (PROFILE) of the Strobe Options menu
From Option 3 (STATUS)
Automatically, as a part of the measurement request process.

These three options are described in the following sections.

Producing Profiles from the PROFILE Menu Option

To produce a Profile from the PROFILE option:

Select Option 4 (PROFILE) from the Strobe Options menu.
Press Enter to display the Strobe- Produce a Performance Profile panel.
Tip
If there is a name in the Sample Data set Name field, it is the sample data set name you last selected on the - Status panel, or the sample data set name for the last Profile request that you made.
Strobe- Produce a Performance Profile Panel
Specify processing options. You can produce a Performance Profile either as a batch job step (background) or online (foreground) by typing the appropriate option code in the Option field, as described below.
1. To select background processing, type B on the Option line. Strobe generates a job stream and either submits it to the internal reader or writes it to a data set, or both, depending on your selection on the Strobe- Select Options For Job Stream Panel.
2. To select foreground processing, type F on the Option line.
AutoStrobe only: Collect Measurement Session History. If you have AutoStrobe installed at your site, you can request that Strobe collect and store historical information as you create a Performance Profile. If this option is specified, Strobe saves selected historical information, as well as some calculated values for the measurement session. For more information, see Collecting Measurement Session History.
Specify the name of the sample data set assigned to the measurement request. For more information, see Specifying Sample Data set Information.
Press Enter to produce the Profiles.

Specifying Sample Data set Information

To specify sample data set information:

If you know the name of the sample data set, type its name in the Sample Dataset Name field.
If you do not know the name of the sample data set, clear the Sample Dataset Name field.

Press Enter. Strobe displays a list of all available sample data sets on the Strobe- Sample Data Set List panel.

Type S to the left of one or more data set names, indicating which Profiles you want to produce.

Strobe- Sample Data Set List Panel

The header line for each request in the Strobe- Sample Data Set List contains

REQ	The request number (if you have typed P or G on the Strobe- Status panel, the appropriate option code precedes the request number).
OWNERID	The user ID or job name that initiated the request.
JOBNAME	The job name of the measured program.
PROGRAM	The name of the measured program.
STEPNAME/STEPNUM	The name or number of the measured step.
STATUS	The status of the session.

A list of sample data sets associated with the request follows this header line. Each list entry shows

DSNAME	The name of the sample data set
STATUS	The status of the sample data set (either open or closed)
SAMPLES	The total number of samples in the data set
EXEC	The number of execution samples in the data set

Creating iStrobe Performance Profiles

If iStrobe is installed at your site, you can specify that Strobe create a compatible format of the Performance Profile. iStrobe enables you to view and analyze the Performance Profile at a workstation using a standard Web browser.

To create an iStrobe Performance Profile and, optionally, transfer it directly to iStrobe, follow these steps:

Strobe- Produce a Performance Profile Panel

Enter I for iStrobe file in the OUTPUT FORMAT field of any of the following panels:
(If the I option is not available, contact your Strobe system programmer, who may need to update the Strobe PARMLIB as described in the .)
Press Enter.
Strobe displays the Strobe- iStrobe Performance Profile Options panel.If you access this panel from the Strobe- Produce a Performance Profile panel, type the name of the iStrobe Performance Profile data file in the ISTROBE DATA FILE field. If you access this panel from either the Strobe- Create an Auto Performance Profile panel or the Strobe- Change an Auto Performance Profile panel, Strobe generates the iStrobe data file name for you.
Strobe- iStrobe Performance Profile Options Panel
Specify the appropriate values in the Strobe- iStrobe Performance Profile Options panel fields, shown here in bold.
- Name is a name that you assign to the iStrobe Performance Profile data file.
  - Name can be as many as 12 characters and must not include spaces. Some sites may need to limit Name to 8 characters.
  - When you open iStrobe and open the Performance Profile, Name will be the default name by which iStrobe refers to the Profile.
- Save into Strobe Insight DB is used to control whether the iStrobe profile data is saved into the Strobe Insight database. This field is optionally displayed depending on the UI_SAVEINDBCTL value specified in the Strobe installation parameters. Its default value is also dependent on the value of UI_SAVEINDBCTL. When this field is displayed, you can override the default value. Doing so could be useful to keep test run data from being included with production run data in the database.
- Overwrite existing Profile applies to the Name field.
  - Enter Y to overwrite an existing iStrobe data file.
  - Enter N if the name in the Name field is not to be replaced. In this case, the iStrobe file transfer function will assign a unique name to the iStrobe data file. The unique name will be built by combining the Short Name and a unique numeric suffix. In the case of duplicate names, the numeric suffix will be incremented by one.
- Description is a phrase that you can use to help identify this iStrobe Performance Profile. This description can be as many as 30 characters and will appear at the top of the iStrobe Measurement Session Data report.
- Code Page is the name of the code page to be used for translation to the ASCII character set from the EBCDIC character set. The code page is set by the value of UI_ICODEPAG parameter of the Strobe parameter data set specified during Strobe installation, but you can change it on this panel.
  - At non-U.S. installations, type your code page. Refer to for code pages that Strobe supports.
  - In the U.S., type IBM-STD. This default code page, supplied with Strobe, will work correctly on most systems. If you are using another transfer method, specify IBM-037.
Specify Y in the Perform Profile Transfer field if you want Strobe to transfer the file to iStrobe. Note that:
- Server is the IP address or domain name of the network location of the directory to which iStrobe Performance Profiles data files are sent. It defaults to the value of UI_ISTRBIP parameter of the Strobe parameter data set specified during Strobe installation, but you may modify it on this panel. Consult your site’s iStrobe administrator to determine the proper value to enter in this field.
- Port Number is the communications port of the iStrobe Profile Manager Server. The default is the value of the UI_ISTRBPRT parameter of the Strobe parameter data set specified during Strobe installation. Consult your site’s iStrobe administrator to determine the proper value to enter in this field.
- Tags are the tags that are associated with this iStrobe Profile when it is created. This field is optional.
- Folder is the logical folder name where the iStrobe Performance Profile datafile is stored/saved for viewing with iStrobe. The maximum length of the Folder value is 16 alphanumeric characters. The default is iStrobe. Refer to the Folder Name column on the my Strobe screen in iStrobe to see the folders currently available, or enter a new name to create a new folder.
- Email Notification Address is an optional e-mail address to receive notification of an iStrobe profile creation. There is no default.
If Strobe for Db2 is installed and you are creating reports for Strobe SQL Analysis, type Y in the SQL Analysis Feature Reports field and press Enter. Strobe displays the Strobe- SQL Analysis Feature Report Settings panel. Specify values for the various SQL Analysis options as described in Ensuring Accuracy of SQL Information. Press Enter.
Strobe creates the iStrobe data file. If you specified Y in the Perform Profile Transfer field and provided the required information, Strobe transfers the file to the specified address.

Ensuring Accuracy of SQL Information

If you specified Y in the SQL Analysis Feature Reports field, Strobe SQL Analysis is invoked when you create the Profile, not when you measure the Db2 application. To ensure the reports produced by Strobe SQL Analysis accurately reflect the state of Db2 subsystem catalog and the access paths and associated catalog statistics at the time of measurement, you should create the Profile as soon as possible after measuring the application. For example, you want to ensure that the set of statistics updated by RUNSTATS used at measurement time are the same as those used when you create the Profile.

Creating a PLAN_TABLE, DSN_FUNCTION_TABLE, and DSN_PREDICAT_TABLE

Before creating a Performance Profile that contains Strobe SQL Analysis reports, you must first do one of the following:

Create a PLAN_TABLE, DSN_FUNCTION_TABLE, and a corresponding DSN_PREDICAT_TABLE if you want SQL statements to be dynamically EXPLAINED.
Select USE EXISTING PLAN-TABLE ROWS under the ACCESS OPTIONS.

Refer to Installing for more information.

Specifying SQL Analysis Feature Report Settings

If you specified Y in the SQL Analysis Feature Reports field on the Strobe- iStrobe Performance Profile Options panel, Strobe displays the Strobe- SQL Analysis Feature Report Settings panel. Scrolling may be required to view all fields. Specify settings for the SQL Analysis Feature (SQLAF) reports.

Strobe- SQL Analysis Feature Report Settings Panel

Report Options

Explain - Type Y to produce a Db2 Explain report. The report provides a convenient way to view Db2 Explain output for an SQL statement. Explain populates the database table PLAN_TABLE with data that describes the access path chosen for an SQL statement by the Db2 optimizer.
Translation - Type Y to produce a translation report that analyzes the results of the Db2 Explain output. The report displays background information relevant to the access path and translation of the access path chosen by the Db2 optimizer for the SQL statement. Background information precedes the translated access path, and includes information such as definitions for synonyms, aliases, views, and referential constraints.
Observations - Type Y to produce the Observations report, which recommends ways to improve the access path chosen by the Db2 optimizer for your SQL statements, and that highlights other potential performance problems related to your database. SQL Analysis makes recommendations based on the contents of PLAN_TABLE, SQL statement text, database schema, catalog statistics used by the Db2 optimizer, and installation-defined resource thresholds.
Statistics - Type Y to produce a Db2 Catalog Statistics report. The report includes the catalog generated by the Db2 RUNSTATS utility for all tables referenced in SQL statements processed by SQL Analysis. The Db2 optimizer uses catalog statistics when it generates access paths for SQL statements. The Db2 Catalog contains tables that together describe the objects in a Db2 subsystem.
Rule Threshold - Type a valid PDS member for in this field that contains a set of rule threshold values to use during generation of the Observations report. The specified member must have been created by building a loadable module using the STRANRDA macro. If you do not specify a value for Rule threshold, SQL Analysis applies default values. Refer to the Installing for a list of the default values.

Statements to Process

Total CPU Percent - When you generate SQL access path information, the value you type in this field specifies the minimum percentage of CPU time used by the SQL statements that you want SQL Analysis to process. Enter a number between 0 and 99; the default value is 2. iStrobe reports on only those statements that use at least that percentage of CPU time.
If you are unsure of the percentage of CPU time to specify, you might want to use Top N Users instead. Top N Users will limit the number of SQL statements processed by SQL Analysis to those statements that use the most CPU time.
Important
You cannot specify a value for both Total CPU Percent and Top N Users.

Top N Users - When you generate SQL access path information, the value you type in this field specifies how many of the most CPU-intensive SQL statements you want SQL Analysis to process, regardless of their actual CPU usage. Enter a value from 1–98, or 99, where 99 means all SQL statements will be processed. The default value is 5. If the number of SQL statements in the Profile data file is fewer than the number you specify, SQL Analysis will process all of the statements.
Warning
Specifying 99, which means that SQL Analysis will process all SQL statements, might significantly increase the time needed to create a Profile and the amount of memory used in the address space.
In addition, if you are using SQL Analysis with DDF reports, you can limit the number of SQL statements processed by SQL Analysis by using DDF thresholds and filters. For more information, refer to the Db2 section of the Using-Strobe-options.

Total Wait Percent - When you generate SQL access path information, the value you type in this field specifies the minimum percentage of wait time used by the SQL statements that you want SQL Analysis to process. Enter a number between 0 and 99; the default value is 2. iStrobe reports on only those statements that use at least that percentage of wait.
Important
You cannot specify a value for both Total Wait Percent and Top N Wait.

Top N Wait - When you generate SQL access path information, the value you type in this field specifies how many of the most wait-intensive SQL statements you want SQL Analysis to process, regardless of their actual wait usage. Enter a value for n between 1 and 20. The default value is 2. If there are fewer than the number you specify, SQL Analysis processes all SQL statements in the Profile data file.
Using Top n Wait Users will give you an understanding of the range of wait percentages for the SQL statements that are executed.

DBRM/Package Name - DBRM/Package name specifies the DBRM or Package for which SQL Analysis produces SQL access path information. If you do not specify a name, SQL Analysis produces information for SQL statements in all DBRMs or Packages observed during measurement. This option helps you focus your performance improvements on the SQL statements within a specific DBRM or package that you suspect is consuming a disproportionate amount of resources.
Important
SQL Analysis reduces the set of SQL statements processed to the value specified in Total CPU Percent or Top N Users after it limits the DBRM named in your list.
Explain Table Creator/Owner for existing Static SQL EXPLAIN data - If this field is populated, SQL Analysis first searches for Static SQL EXPLAIN data in the existing Db2 Explain tables created using this qualifier. If the field is not populated or no EXPLAIN data can be found for the Static SQL statement, then a Dynamic EXPLAIN takes place using the value specified in the next field.Explain Table Creator/Owner Options

Explain Table Creator/Owner for Dynamic EXPLAIN of SQL Statements - If this field is populated, then SQL Analysis uses this value in a SET CURRENT SQLID statement. Therefore, the user ID executing the SQL Analysis must have the ability to use the specification (that is, Primary or Secondary Authorization ID). If the field is not populated, then the user ID executing the SQL Analysis is used.
Important
A set of Db2 Explain tables must exist, with either the specified panel value or if omitted, the user ID executing the SQL Analysis.

Db2 Options

SSID - Specifies the ID of the Db2 subsystem to which Strobe SQL Analysis connects. Db2 Subsystem overrides the subsystem ID captured during measurement. If you do not specify a Db2 Subsystem, the default value is the subsystem ID captured during measurement.

Db2 Loadlib Override

LOADLIB - Enables you to override the Db2 load library DSN value for the Db2 subsystem to which Strobe SQL Analysis is connecting. This value is originally loaded from UI_STRDB2LD as specified in the Strobe parameter data set and is an ISPF persistent value.

Producing Profiles from the STATUS Menu Option

To produce a Performance Profile from the Strobe- Status panel:

Select Option 3 (STATUS) from the Strobe Options menu.
Press Enter to display the Strobe- Status panel.
Type either P (Profile) or G (default Profile) for requests that have a closed sample data set.
- To produce a Performance Profile in background using the installation defaults, type G (default Profile) to the left of the request number.
- To produce a Performance Profile with customized report parameters, type P (Profile) to the left of the request number.

Strobe- Status Panel

Press Enter to continue the processing.
- If you chose default Profile (G), Strobe displays the Strobe- Select Options For Job Stream panel before your request is processed as a batch job step. See Selecting Job Stream Options.
- If you are customizing the Profile (P), Strobe displays the Strobe- Produce a Performance Profile panel. See Customizing Performance Profiles.

When you choose these options for a request that has more than one sample data set, Strobe displays the Strobe- Sample Data set List, from which you can make your selections.

To select a sample data set, type S to the left of the sample data set name.

Strobe- Sample Dataset List for a Default Performance Profile Panel

Processing Multiple Datasets

If you choose more than one sample data set from the Strobe- Sample Dataset List, Strobe processes each one in turn. To skip a sample data set, clear the Sample Dataset Name field and press Enter to display the Strobe- Produce a Performance Profile panel with the name of the next sample data set. To cancel processing, press End.

When you choose background processing for multiple sample data sets, Strobe creates the Profiles as multiple steps of the same job.

Producing Profiles Automatically

To automatically create a Performance Profile:

Type Y in the Auto Profile Creation field on the Strobe- Add Active Request panel or the Strobe- Add Queued Request panel.
Press Enter to display the Strobe- Create an Auto Performance Profile panel.
Strobe - Create an Auto Performance Profile Panel
Specify the values for the fields on this panel as you would on the Strobe- Produce a Performance Profile panel.
Ensure that the job statement information at the bottom of the panel is valid.
Important
To prevent exposing user logon passwords, the PASSWORD keyword is not allowed on the job statement.
Press Enter to return to the panel from which you started (Strobe- Add Active Request or Strobe- Add Queued Request).
If iStrobe is installed at your site, you can use Strobe to create an iStrobe Performance Profile automatically upon completion of the measurement session. To automatically create a data file for iStrobe, specify I in the Output Format field and follow the instructions in Creating iStrobe Performance Profiles.
For information on changing or canceling an automatic Performance Profile request, see Changing Automatic Profile Requests.