Clear schema cache for cross-cluster queries
Applies to: ✅ Azure Data Explorer
When running a cross-cluster query, the cluster that performs the initial query interpretation must have the schema of the entities referenced on the remote clusters. Sending the command can be an expensive network operation and therefore the remote schema entities are cached.
Any changes to the schema of the remote entity may result in unwanted effects. For example, new columns aren't recognized or deleted columns may cause a 'Partial Query Error' instead of a semantic error. For more information, see Cross-cluster queries and schema changes.
You can use the following command when you need to refresh the schema without waiting for the expiry time of the cache.
Permissions
You must have at least Database User, Database Viewer, or Database Monitor permissions to run this command. For more information, see role-based access control.
Syntax
.clear cache remote-schema cluster('ClusterName').database('DatabaseName')
Learn more about syntax conventions.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
| ClusterName | string |
✔️ | The name of the cluster containing the database for which to clear the cache. |
| DatabaseName | string |
✔️ | The name of the database for which to clear the cache. |
Returns
The command returns a table with the following columns:
| Column | Type | Description |
|---|---|---|
| NodeId | string |
Identifier of the cluster node |
| Status | string |
Succeeded/Failed |
Example
.clear cache remote-schema cluster("cluster1").database("database1")
Returns
| NodeId | Status |
|---|---|
| 0 | Cache cleared for database database1 |