I have a question about Firestore Indexing pricing. I've setup an index in a collection for a "tags" array field with timestamp descending and wondering if this will cost anything. I am aware that the actual storage taken up by the index will cost something, but are there any other fees like firestore reads that should be taken into account?
Thanks so much!
The only cost for indexes is their storage cost. There is no charge for accessing them or writing them, beyond the normal read/write costs for those operations (doc reads/doc writes/egress bandwidth).
The only other time I tend to think about the cost is when you run a query with no results. Such a query is charged as a single document read, and I mentally always map that one to "it's for reading the index". That's not really how it works though, as there is no charge for reading the index if there are resulting documents. But somehow it sticks in my mind, so... ¯\_(ツ)_/¯
