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Performance recommendations
This documentation contains general performance tips and recommendations to improve performance.
General performance overview
This documentation describes what takes place during product execution and presents performance tips and recommendations regardless of the platform on which a specific HCL Link product is running.
Command Server operation overview
The first step in trying to achieve performance improvements running the Command Server in your environment is to understand Command Server operation.
Command Server work and data files
Depending on the conditions of the transformation, such as input data file size and processing complexity, work and data files can significantly affect performance.
Reusing work files
Depending on the conditions of the transformation, such as input data file size and processing complexity, work and data files can significantly affect performance. When possible, reusing work files can produce measurable performance gains.

Performance recommendations
This documentation contains general performance tips and recommendations to improve performance.
- General performance overview
  This documentation describes what takes place during product execution and presents performance tips and recommendations regardless of the platform on which a specific HCL Link product is running.
  - Performance measurement factors
    When analyzing how well an application has performed, there are potentially a large number of measurements that can be used to gauge workload efficiency in terms of the specific resources the application used.
  - Command Server operation overview
    The first step in trying to achieve performance improvements running the Command Server in your environment is to understand Command Server operation.
    - Command Server execution overview
      When you want to achieve performance improvements when running the Command Server in your environment, you must understand Command Server execution.
    - Command Server work and data files
      Depending on the conditions of the transformation, such as input data file size and processing complexity, work and data files can significantly affect performance.
      - Reusing work files
        Depending on the conditions of the transformation, such as input data file size and processing complexity, work and data files can significantly affect performance. When possible, reusing work files can produce measurable performance gains.
    - Command Server paging settings
      To minimize the memory footprint during transformation, HCL Link keeps only a subset of the work and data file information in memory at a given time.
  - Map performance and tuning best practices
    Many functions available to users for developing HCL Link maps are very powerful and can perform difficult and complicated tasks. Some functions may sacrifice performance for powerful capabilities, and it is important to understand the implications of these.
- Glossary
  Performance related terms and definitions.

Reusing work files

Depending on the conditions of the transformation, such as input data file size and processing complexity, work and data files can significantly affect performance. When possible, reusing work files can produce measurable performance gains.

About this task

Work files contain metadata about the various type objects found in each input data file. If the data content is static, this metadata can be reused in subsequent runs. Reusing work files allows the transformation engine to bypass the validation step for these sources. Reducing the number of steps results in a shorter overall execution time.

When possible, reusing work files can produce measurable performance gains, especially in input data files requiring complex validation logic. This option is ideal for map processes that make use of static data, such as lookup tables. Work file reuse is specified separately for each input card, either as an execution command or as an option in the Map Designer. Reusing work files with an execution command is done with the W option on the input card override (-I) execution command.

To reuse work files, you must generate a work file.

To generate a work file

Procedure

Specify an input card override -I execution command for the corresponding input source for a compiled map with the (W) reuse option.
Execute the map.
A work file is generated.

Results

Subsequent map executions with the same input override options will reuse the generated work file. As mentioned previously, this option is ideal if the data content is static. If the data content changes, the work file should be regenerated.

To regenerate a work file

Procedure

Remove the old work file.
Specify an input card override -I execution command for the corresponding input source for a compiled map with the (W) reuse option.
Execute the map.
A work file is generated.

Results

A generated work file can be used to determine the amount of workspace required for a given input source. This can be helpful when using workspace options such as -WM.

See the Command Server documentation and the Execution Command documentation for more information about work file reuse.