[stickfigure]

You misunderstand how GAE indexes work.

There are two kinds of indexes:

* multi-property indexes which you configure via datastore-indexes.xml (or yaml). You can remove these by removing them from the xml/yaml and vacuuming.

* single-property indexes, which you decide when you define your data model. You can't vacuum these, and they are defined on a per-entity basis. The only way to make them go away is to re-save the relevant entities without the index defined. Note: multiproperty indexes require single-property indexes on all the properties covered.

These single-property indexes are almost certainly causing your high write op counts. You really should examine your data model with this new understanding; by removing unnecessary single-property indexes, you may be able to dramatically reduce your bill.