Improving query performance and results

You can change system parameters to improve query performance and results.

Before you begin

You must have the Information Governance Catalog Glossary Administrator or the Information Governance Catalog Information Asset Administrator role.

Ensure that you have enough memory to run queries.

About this task

When you run queries on a large number of assets, or with many conditions, the performance might be slow. To improve the performance, complete the following tasks.

Procedure

  1. Run iisAdmin commands to adjust settings. Typically, these commands are run once, or until you are satisfied with query performance.
    1. Open a command-line window on the server where InfoSphere Information Governance Catalog is installed.
    2. In the command shell, go to installation_directory\ASBServer\bin directory, where installation_directory is the directory where IBM InfoSphere Information Server was installed.
    3. At the command-line prompt, type the command to change the system parameter according to your needs.
      Table 1. Changing system parameters by running iisAdmin commands
      To do this action Run this command
      Improve query performance
      Microsoft Windows
      iisAdmin.bat -set -key com.ibm.iis.gov.vr.setting.queryResultRecommendedBatchSize -value 50000
      UNIX
      iisAdmin.sh -set -key com.ibm.iis.gov.vr.setting.queryResultRecommendedBatchSize -value 50000
      Increase the number of query rows that are saved to a file
      Microsoft Windows
      iisAdmin.bat -set -key com.ibm.iis.gov.vr.setting.maxRowsInSearchResultSheet -value max_rows
      UNIX
      iisAdmin.sh -set -key com.ibm.iis.gov.vr.setting.maxRowsInSearchResultSheet -value max_rows

      The variable max_rows is the maximum number of rows to save.

      Note: Saving to XLS format is limited to 65,535 rows, even if max_rows was set higher. To view more results in Microsoft Excel 2003 or later, save to a CSV file, and then open the CSV file with Excel.
      View All Query Result Instances
      Microsoft Windows
      iisAdmin.bat -set -key com.ibm.iis.gov.vr.setting.maxObjectsPerRefInSearchResults -value search_results
      UNIX
      iisAdmin.sh -set -key com.ibm.iis.gov.vr.setting.maxObjectsPerRefInSearchResults -value search_results

      The variable search_results is the number of results to display in reports.
      It is not necessary to restart WebSphere Application Server. InfoSphere Information Governance Catalog picks up the new value automatically, within a minute.
  2. Configure the directory where query results are written. The directory must have enough space for results of large queries. If possible, specify a directory on a fast disk, for example SSD. For details, see Configuring the directory for temporary search and query results.