A memory control apparatus which controls access to a shared memory for each transaction. The apparatus includes a management unit that stores versions of data stored in the shared memory, a log storage unit that stores an update entry including a version of data subjected to an update operation in response to execution of an update operation on the shared memory in processing each transaction, and a control unit that writes a result of processing corresponding to execution of a relevant update operation to the shared memory when a request to commit a transaction has been given, and a relevant update entry version matches a corresponding version stored in the management unit, or re-executes the update operation and writes a result of re-execution to the shared memory when the update entry version does not match the corresponding version in the management unit.