Don't know of any way to kill just the query, Didrik. Since the query process is 100% read-only, no damage to the database can happen by killing the process. The only issue would be if there are unsaved changes in the project before you start the query.... they would most likely be lost unless you are prompted for an auto-recovery file when you relaunch AC. Well, there might be some temporary files left hanging about from the query somewhere, too. But, no harm to the project itself.
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB