In the case where an update is performed to a site that is not capable of two-phase commit and where a multi-site update transaction is required, Ingres Star simulates two-phase commit. It does this by first sending a prepare-to-commit to all sites that are capable of that protocol, then sending a commit to the single site not capable of two-phase commit, and finally sending commits to all other prepared sites. Note that Ingres Star only supports simulated two-phase commit when a single site not capable of two-phase commit is involved in a multi-site update. If more than one site not capable of two-phase commit is updated, Ingres Star refuses the attempted update.