Step 3: Specifying counters, objects, time frame, and output

About this task

When you have performed Step 2: Choosing a subsystem and specifying an analysis type, the third page of the long-term analysis wizard is displayed. This page differs somewhat depending on the analysis type you specified in the previous step. At first, this topic shows and describes the more flexible specifications applicable to the first four analysis types (Weekly view by day, Daily view by hour, View of a period of time, and Bar chart), and the similarities of this page that apply to all analysis types. Characteristics of the pie chart analysis types details the specifications for remaining pie chart presentations (which is basically a more restrictive use of 1-to-n and n-to-1 relations between counters and objects).
Figure 1. Long-Term Analysis – The Counter and Object Selection window
This figure is a graphical representation of the Counter and Object Selection window from a long-term analysis.
Use this page to specify which counters and objects to consider for the analysis, the time frame to include, and the name to be used for saving the analysis result.
  • For a long-term analysis usually only a subset of counters and objects is of interest. This page is used to specify which of them are to be included in the analysis.
    • Counters to display shows a tree view of selectable counters. You can expand or collapse the tree items by clicking the plus sign (+), respectively the minus sign (-), or by double-clicking the corresponding tree item.

      You use this list to specify which counters to consider for the long-term analysis, provided they pertain to selected active objects (see later in this topic).

    • Objects to display shows a tree view of selectable objects. You can expand or collapse the tree items by clicking the plus sign (+), respectively the minus sign (-), or by double-clicking the corresponding tree item. The list of objects contains those objects that were identified as active objects in the selected bpd files during preprocessing, and which belong to the selected subsystem.

      You use this list to specify which objects to consider for the long-term analysis, provided they pertain to selected counters (see previous information).

    In both trees you can select counters, respectively objects, on different levels and in any combination. The tree hierarchies denote the counter and object hierarchies, not selectable groups of counters or groups of objects. For example, the Getpage total count contains the sum of the Getpage random, Getpage ridlist, and Getpage sequential counts; nevertheless, you can select Getpage total and Getpage random only, which will only show these two counters in the result.

    As indicated, the selections of counters and objects are interrelated. Technically, both selections act as filters, which means that the analysis result includes only information about selected counters pertaining to selected objects. Practically, deliberate selections of counters and objects on this page permit two different but powerful views:
    • If you are interested how a single counter behaves in several objects (for example, to compare the Getpage sequential counts of several objects), you select one counter and several objects. This is basically a 1-to-n relation between counters and objects. However, you can also set up a few-to-many relation, for example, to compare a few counters in several objects.
    • If you are interested how several counters behave in one object (for example, to analyze the key counters of an object), you select the counters and a single object. This is basically a n-to-1 relation between counters and objects. However, you can also set up a many-to-few relation.
    As pointed out, you are not restricted in your choice of n-to-m relations between counters and objects. The long-term analysis function processes any of your selections, independently of whether they make sense or how complex the graphical representation of the result becomes. Start with simple 1-to-1, 1-to-n or n-to-1 counter-to-object relationships until you become familiar with the result. Refine these relations step by step.

    Note that this degree of freedom in selecting counters and objects for the long-term analysis applies to the analysis types Weekly view by day, Daily view by hour, View of a period of time, and Bar chart. The selection of counters and objects for pie chart results is more restrictive (1-to-n and n-to-1) to avoid complex results. The details are described in Characteristics of the pie chart analysis types.

  • The Time frame group box shows, by default, the earliest and the latest timestamp of data found in the selected bpd files. The controls can be used to limit the time frame by changing one or both timestamps. Only data from the selected bpd files with timestamps between the default, or specified, From and To dates is used for the long-term analysis. Reset From and Reset To reset any specified values to the default values. These push buttons are helpful if you change your mind; you do not need to remember the earliest and latest timestamps.
  • The Graphic file name field shows the proposed name under which the result from the long-term analysis will be saved for later viewing. The proposed name can be changed, if required. The syntax of proposed names is explained in Viewing the result of a long-term analysis.
  1. Select the Counters to display by selecting or clearing the check boxes as required. At least one counter must be selected.
  2. Select the Objects to display by selecting or clearing the check boxes as required. At least one object must be selected.
  3. Review the information under Time frame. If required, change one or both timestamps. To enter a different timestamp, overwrite the timestamp. Adhere to the format, otherwise, this function might not be able to process the appropriate records from the bpd files, or might not be able to continue.
  4. Review the proposed name in the Graphic file name field. Change it as required.
  5. Click Create, or click Back to return to the previous page.

    The wizard creates the graphical result and saves it under the specified name. If the name already exists, you are given the choice to replace the existing graphic file or to save the new one under a different name.

    When the long-term analysis wizard finishes, the result is immediately shown in a new browser window and in the right pane of the Buffer Pool Analysis main window. In addition, the result is saved in the Results subfolder of the Long Term Analysis folder for later viewing.

  6. Continue with Viewing the result of a long-term analysis.