6. A method comprising: in response to receiving a database statement, determining whether a user that initiated the database statement is authorized to access data from a plurality of data realms; for each data realm of the plurality of data realms, determining an authorization result and generating a data realm predicate that reflects the authorization result; wherein the data realm predicate is one of a plurality of data realm predicates generated for the database statement; wherein a particular predicate comprises the plurality of data realm predicates; performing one or more normalizations on the particular predicate to remove one or more data realm predicates from the plurality of data realm predicates to generate a normalized predicate that does not include the one or more data realm predicates; generating an execution plan based on the normalized predicate and not based on the one or more data realm predicates.
6. A method comprising: in response to receiving a database statement, determining whether a user that initiated the database statement is authorized to access data from a plurality of data realms; for each data realm of the plurality of data realms, determining an authorization result and generating a data realm predicate that reflects the authorization result; wherein the data realm predicate is one of a plurality of data realm predicates generated for the database statement; wherein a particular predicate comprises the plurality of data realm predicates; performing one or more normalizations on the particular predicate to remove one or more data realm predicates from the plurality of data realm predicates to generate a normalized predicate that does not include the one or more data realm predicates; generating an execution plan based on the normalized predicate and not based on the one or more data realm predicates. 7. The method of claim 6 , wherein performing one of the one or more normalizations comprises: identifying a portion of the particular predicate that comprises an inverted data realm predicate that is AND'd with a false predicate; replacing the portion of the particular predicate with the false predicate.