Reducing limit over the life of a datastore query iterator. by dhermes · Pull Request #1787 · googleapis/google-cloud-python

Sorry: When a query is continued, it may contain an offset. But like the limit the offset should always be decreasing. What I really mean:

Always use a cursor to step to the next batch of a query, never an offset.

Sometimes you need to go through batches of offset, in which you'll issue multiple queries with decreasing offsets. This is ok.