The Stop button is used to cancel a command.
A Stop operation stops current processing and prompts for the next command. If a command file was being processed, you are prompted for an action to take (Stop command file, Continue, or Exit ISQL). These actions can be controlled with the ISQL ON_ERROR option (see "SET OPTION statement").
When an abort is detected, one of three different errors will be reported depending upon when the abort is detected.
ISQL command terminated by user
stops processing immediately and the database transaction is left alone.
Terminated by user -- transaction rolled back
Since data definition commands all perform a COMMIT automatically before the command starts, the effect of the ROLLBACK is to just cancel the current command.
This message also occurs when the database engine is running in bulk operations mode executing a command that modifies the database (INSERT, UPDATE, and DELETE). In this case, ROLLBACK cancels not only the current command, but everything that has been done since the last COMMIT. In some cases, it may take a considerable amount of time for the database engine to perform the automatic ROLLBACK.
Statement interrupted by user.
The effects of the current command are undone, but the rest of the transaction is left intact.