1 entity delete = 2 Writes + 2 Writes per indexed property value + 1 Write per composite index value
All from this page: http://code.google.com/appengine/docs/billing.html#Billable_... And more about why it is so: http://code.google.com/appengine/articles/life_of_write.html
Well, the OP is just another coder who can't read docs, but can write a blog.
The correct behavior would be to recalculate the indices just once, instead of reindexing after every single delete operation.
It then becomes
2*entities + 2*indexed property values + composite index values
2*entities + 2*entities*indexed property values + entities*composite index values
The correct behavior would be to recalculate the indices just once, instead of reindexing after every single delete operation.
It then becomes
operations to delete all entities in the datastore, instead of operations.