Return a number which is no longer available as hook_update_N().
If you remove some update functions from your mymodule.install file, you should notify Drupal of those missing functions. This way, Drupal can ensure that no update is accidentally skipped.
Implementations of this hook should be placed in a mymodule.install file in the same directory as mymodule.module.
An integer, corresponding to hook_update_N() which has been removed from mymodule.install.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_update_last_removed() {
// We've removed the 5.x-1.x version of mymodule, including database updates.
// The next update function is mymodule_update_5200().
return 5103;
}