When you trigger an update policy with a command that adds data to a source table, data also appends to a target table. The target table can have a different schema, retention policy, and other policies from the source table. For example, a high-rate trace source table can contain data formatted as a free-text column. The target table can include specific trace lines, with a well-structured schema generated from a transformation of the source table's free-text data using the parse operator.

For more information, see update policy.

This article describes how to create an update policy on a table in Real-Time Intelligence using the .alter table update policy command.

• A workspace with a Microsoft Fabric-enabled capacity
• A KQL database with editing permissions

1. Browse to the main page of your KQL database.

2. Select New > Table update policy.

   :::image type="content" source="media/table-update-policy/new-policy.png" alt-text="Screenshot of the KQL Database home tab showing the dropdown menu for creating new entities. The dropdown option for creating a table update policy in Real-Time Intelligence is highlighted." lightbox="media/table-update-policy/new-policy.png":::

   The .alter update policy command is automatically populated in the Explore your data window.

   :::image type="content" source="media/table-update-policy/policy-in-window.png" alt-text="Screenshot of the Update table policy command in the Explore your data window in Real-Time Intelligence in Microsoft Fabric." lightbox="media/table-update-policy/policy-in-window.png":::

3. Enter the parameters of your table update policy, and then select Run. For more information on these parameters, see .alter table update policy.

• .show table update policy
• Query data in a KQL queryset