with-transaction executes body within a transaction for database (which defaults to *default-database*). The transaction is committed if the body finishes successfully (without aborting or throwing), otherwise the database is rolled back.
The following example shows how to use
with-transaction to insert a new record, updates the department number of employees from 40 to 50, and removes employees whose salary is higher than 300,000. If an error occurs anywhere in the body and an
throw is executed, none of the updates are committed.
LispWorks User Guide and Reference Manual - 20 Sep 2017