The Firebird 5.0 Language Reference | MON$STATEMENTS | Using MON$STATEMENTS To Cancel A Query

Using `MON$STATEMENTS` to Cancel a Query

Monitoring tables are read-only.However, the server has a built-in mechanism for deleting (and only deleting) records in the MON$STATEMENTS table, which makes it possible to cancel a running query.

Note

Notes

If no statements are currently being executed in the connection, any attempt to cancel queries will not proceed
After a query is cancelled, calling execute/fetch API functions will return an error with the isc_cancelled code
Subsequent queries from this connection will proceed as normal
Cancellation of the statement does not occur synchronously, it only marks the request for cancellation, and the cancellation itself is done asynchronously by the server

Example

Cancelling all active queries for the specified connection:

DELETE FROM MON$STATEMENTS
  WHERE MON$ATTACHMENT_ID = 32

Using MON$STATEMENTS To Cancel A Query

Using MON$STATEMENTS to Cancel a Query

Using `MON$STATEMENTS` to Cancel a Query