Vincent-Philippe Lauzon has an announcement:
Kusto databases, either in Fabric (KQL Database) or in Azure (Azure Data Explorer), are optimized for append ingestion.
In recent years, we’ve introduced the .delete command, allowing you to selectively delete records.
In February, we introduced the .update command in public preview. This command allows you to update records by deleting existing records and appending new ones in a single transaction.
Today, the .update is Generally Available (GA)!
Click through for more details, including a link to the documentation, where you can see several examples of the syntax.