diff --git a/data-explorer/kusto/management/alter-query-acceleration-policy-command.md b/data-explorer/kusto/management/alter-query-acceleration-policy-command.md index 909267a5d2..7549cc4ccc 100644 --- a/data-explorer/kusto/management/alter-query-acceleration-policy-command.md +++ b/data-explorer/kusto/management/alter-query-acceleration-policy-command.md @@ -3,7 +3,7 @@ title: .alter query acceleration policy command description: Learn how to use the .alter query acceleration policy command to accelerate queries over external delta tables. ms.reviewer: sharmaanshul ms.topic: reference -ms.date: 09/16/2025 +ms.date: 11/30/2025 --- # `.alter query acceleration policy` command @@ -30,7 +30,9 @@ You must have at least [Database Admin](../access-control/role-based-access-cont | _JSON-serialized policy_ | `string` | :heavy_check_mark: | String literal holding a [JSON property bag](#json-property-bag). | ### JSON property bag + ::: moniker range="microsoft-fabric" + | Property | Type | Required | Description | | ------------------- | ---------- | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | IsEnabled | `Boolean` | :heavy_check_mark: | Indicates whether the policy is enabled. | @@ -38,9 +40,11 @@ You must have at least [Database Admin](../access-control/role-based-access-cont | HotWindows | `DateTime` | | One or more optional time windows. Delta data files created within these time windows are accelerated. | | MaxAge | `Timespan` | | The external table returns accelerated data if the last index refresh time is greater than @now - MaxAge. Otherwise, the external table operates in non-accelerated mode. Default is 5 minutes. Minimum is 1 minute. This property can also be overridden at query time by using the [`external_table()` function's](../query/external-table-function.md) `MaxAgeOverride` parameter. | | HotDateTimeColumn | `String` | | Optional. The name of a datetime column in the Delta table whose values will be used to determine hot-cache eligibility. When set, data files whose rows have values within the configured Hot period (and/or HotWindows) are selected for caching. | + ::: moniker-end ::: moniker range="azure-data-explorer" + | Property | Type | Required | Description | | ------------------- | ---------- | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | IsEnabled | `Boolean` | :heavy_check_mark: | Indicates whether the policy is enabled. | @@ -49,9 +53,12 @@ You must have at least [Database Admin](../access-control/role-based-access-cont | MaxAge | `Timespan` | | The external table returns accelerated data if the last index refresh time is greater than @now - MaxAge. Otherwise, the external table operates in non-accelerated mode. Default is 5 minutes. Minimum is 1 minute. This property can also be overridden at query time by using the [`external_table()` function's](../query/external-table-function.md) `MaxAgeOverride` parameter. | | ManagedIdentity | `string` | | Optional managed identity for which the query acceleration background operations are executed. This identity must have relevant delta table permissions and must be enabled for AutomatedFlows in the cluster / database managed identity policy. For more information, see [Managed identities overview](/azure/data-explorer/managed-identities-overview). | | HotDateTimeColumn | `String` | | Optional. The name of a datetime column in the Delta table whose values will be used to determine hot-cache eligibility. When set, data files whose rows have values within the configured Hot period (and/or HotWindows) are selected for caching. | + ::: moniker-end + > [!NOTE] -> Query acceleration is applied to data within a specific time period, defined as `timespan`, starting from the `modificationTime` as stated for each file in the [delta log](https://github.com/delta-io/delta/blob/master/PROTOCOL.md#add-file-and-remove-file). +> +> Query acceleration is applied to data within a specific time period, based on the `modificationTime` as stated for each file in the [delta log](https://github.com/delta-io/delta/blob/master/PROTOCOL.md#add-file-and-remove-file) by default. You can override the default behavior, by specifying the _HotDateTimeColumn_ property in the policy. ### Example @@ -72,17 +79,23 @@ The command returns a table with one record that includes the modified policy ob | EntityType | `string` | The type of the entity the policy applies to - `ExternalTable` | ## Example + ::: moniker range="microsoft-fabric" + ```Kusto .alter external table MyExternalTable policy query_acceleration '{"IsEnabled": true, "Hot": "1.00:00:00", "HotWindows":[{"MinValue":"2025-07-07 07:00:00","MaxValue":"2025-07-09 07:00:00"}], "MaxAge": "00:05:00", "HotDateTimeColumn":"dt1"}' ``` + ::: moniker-end ::: moniker range="azure-data-explorer" + ```Kusto .alter external table MyExternalTable policy query_acceleration '{"IsEnabled": true, "Hot": "1.00:00:00", "HotWindows":[{"MinValue":"2025-07-07 07:00:00","MaxValue":"2025-07-09 07:00:00"}], "MaxAge": "00:05:00", "ManagedIdentity": "12345678-1234-1234-1234-1234567890ab", "HotDateTimeColumn":"dt1"}' ``` + ::: moniker-end + ## Related content - [Query acceleration policy](query-acceleration-policy.md)