GAE: About the Usage of High Replication Data

Question

I'm using Google App Engine and High Replication Datastore.

I checked the Dashboard of one of my GAE app today, I found that High Replication Data became 52%, 0.26 of 0.50 GBytes in the Billing Status.

I don't use so much data for the app, so I also checked Datastore Statistics and Total number of entities is about 60,000 and Size of all entities is only 42 MBytes, which is far from 0.26 GBytes.

What is the difference between the Usage in the Dashboard and in the Datastore Statistics? And how can I reduce the former Usage?

Thank you.

Answer 1

Because the datastore creates automatic indexes for your entities. In addition if you have custom indexes, they will also need storage.

You can reduce this by removing unused indexes and by not indexing properties, which are not needed for queries (setting indexed=false).

In general however, you need to get used to the idea that the storage for your entities is not the same as total storage needed for the datastore ;)