Displaying Bottleneck Candidates

1. In the context menu of the database system administrator or the logged-on database user, choose  Performance  SQL Performance Analysis . Configure the SQL performance analysis as described in Configuring the SQL Performance Analysis.

2. At the bottom of the page, enter the number of SQL statements that you want to display and choose Get Bottleneck Candidates.

You can configure filters. The following filter types are available:

• Cumulative filters (for example cumulated read pages, runtime, selectivity)

  These filters use the information that the system collects during simple SQL monitoring. The system accumulates the properties of the single executions for each SQL statement.

  They help you find those SQL statements that the system runs frequently. Minor improvements in the performance of such SQL statements can result in large performance gains in the overall system.

• Single filters (for example read pages, runtime, selectivity)

  They help you find those SQL statements for which single executions are particularly slow (for example only for specific parameter values).

Adding Filters

1. Open the Filters section.

2. Choose Add.

3. Choose a filter from list to add to the analysis.

   Filter Name	Filter Condition
   Cumulated Read Pages	Total pages accessed by all executions of individual SQL statements
   Cumulated Runtime	Total runtime (in s) of all executions of individual SQL statements
   Cumulated Selectivity	Total selectivity (in s) of all executions of individual SQL statements
   Read Pages	Pages accessed by single executions of individual SQL statements
   Runtime	Runtime (in ms) of single executions of individual SQL statements
   Selectivity	Selectivity (in %) of single executions of individual SQL statements

4. In the section Filter Detail below the filter table, enter a value for the filter condition.

5. Choose Add.

   Only SQL statements that fulfill at least one of the filter conditions are displayed from now on (OR operator).

Changing Filters

1. Select the filter in the filter table.

2. Choose Edit.

3. Enter the new filter condition.

4. Choose Update.

Removing Filters

Select the filter in the filter table and choose Remove.

1. In the Bottleneck Candidates section you can refresh the list of bottleneck candidates.

2. In the bottleneck candidates list, select the bottleneck candidate.

3. Double click or choose .

   The Bottleneck Candidate Detail tab page is displayed. For more information, see Analyzing Bottleneck Candidates.

You can choose the start time from which bottleneck candidates are displayed:

• Last Restart Database

• Last Reset of SQL Monitoring

Custom Layout

The default layout of the bottleneck candidates list includes the most frequently used columns.

To change the layout, choose and add or remove columns.

Display Variants

Display variants are pre-defined column sets. You can choose different display variants from the Display Variant list.

To change the definition of a display variant:

1. Choose .

2. Select the display variant that you want to change.

3. Add or remove columns.

Sorting the Bottleneck Candidates List

You can sort the results by click on the respective column header.

To specify multiple sorting criteria, choose .