Function StorePartitionKey 

pub unsafe fn StorePartitionKey(
    arg_rel: *mut RelationData,
    arg_strategy: i8,
    arg_partnatts: i16,
    arg_partattrs: *mut i16,
    arg_partexprs: *mut List,
    arg_partopclass: *mut Oid,
    arg_partcollation: *mut Oid,
)