1. A method comprising: generating multiple versions of first metadata describing characteristics of a space within a database, each different version of the multiple versions generated in response to one or more different changes in one or more of the characteristics of the space; maintaining first proxy data that indicates a location of a current version of the multiple versions of the first metadata; generating a compiled plan for executing one or more database operations with respect to items in the space within the database, the compiled plan including a reference to a location of the first proxy data; while executing the compiled plan, based on the reference to the first proxy data in the compiled plan: determining the location of the current version of the first metadata using the first proxy data, accessing the current version of the first metadata at the determined location, and utilizing the current version of the first metadata to execute at least an aspect of the one or more database operations; wherein the method is performed by one or more computing devices.