Commits an in-progress transaction on the specified connection resource and
begins a new transaction. PHP applications normally default to AUTOCOMMIT
mode, so db2_commit() is not necessary unless AUTOCOMMIT
has been turned off for the connection resource.
Замечание:
If the specified connection resource is a persistent connection, all
transactions in progress for all applications using that persistent
connection will be committed. For this reason, persistent connections are
not recommended for use in applications that require transactions.