A method of transferring data between database locations comprising: providing a location reference comprising location values of one or more data collections stored in a database; providing an indicator in association with at least one data collection of the one or more data collections, the indicator being provided in response to initiation of a transfer process of the at least one data collection from a first location of the database to a second location of the database; wherein the indicator is changeable between a first state and a second state, the first state being indicative of the initiation of the transfer process; and as part of the transfer process of the at least one data collection, selectively updating a location value of the at least one data collection in the location reference, in dependence on a determination of whether the indicator is in the first state or the second state.