To optimize query performance, you must collect statistics on the data that is being queried. You can collect statistics in the IBM Cloud Pak for Data web client.

1. On the navigation menu, click Data > Data virtualization.
   The service menu opens to the Data sources page by default.
2. On the service menu, click Virtualized data.
   On the Virtualized data page, you can see a list of virtualized tables and when statistics were last collected for each table.

   
3. To view statistics for a virtualized table, click the overflow menu and select View statistics job.
   The Jobs page shows details about the statistics that were collected.

   
   1. To change the job description, notification details, or job schedule, click Edit job on the Jobs page and make the necessary changes.
   2. Click Next and then click Finish to save your changes.
4. To start a statistics collection job for a virtualized table, click the overflow menu for a table and select Collect statistics.
   Tip: If the Collect statistics option is not in the overflow menu, delete the current statistics collection job. See step 5.
   1. On the Collect statistics page, select the columns that you want to collect statistics for.
      
   2. Select the statistic type, either Remote catalog or Remote query. The Remote catalog statistics type is not supported for all data sources. For more information, see Limitations for collecting statistics in Data Virtualization.
   3. Click Schedule job. On the Create new job page, you can change the job description or notification details. Click Next.
   4. Set the schedule for the job to run one or more times. Click Next and then click Schedule.
   5. When the job completes, click the overflow menu for the table and select View statistics job.
5. To delete a statistics collection job for a virtualized table, on the Virtualized data page, on the table row, click the overflow menu and select Delete statistics job.