Exercise examples of tile storage (saving, indexing, and querying)

[oubiwann]

Background on missing work ... here's what's covered in tickets so far:

• A high-level set of possible raster methods are being tracked in Compile a list of queries that will be most often used #1
• There's a ticket to research the underlying theories and experimental practice on using distributed KVs for raster data storage in Examine the research on distributed KV raster data #2
• There are related service- and db-level API tickets in Implement low-level DB component queries #9, Implement protobuf messages #10, and Implement gRPC API #11
• Ingest and sample data are covered in Ingest sample raster images #12 and Run test queries against sample data #13

However ... there's something missing: work that needs to be done between the second bullet above, and all the others. Namely:

• Explore mechanisms for storing, indexing, and retrieving raster data #25 - Based upon the reading (Examine the research on distributed KV raster data #2), work out one or more possible mechanisms for storing and indexing the raster data
• Spike code for indexing mechanisms #26 - Spike some code that explores these mechanisms
• Examine the spikes against various expected queries
• Examine them against the underlying database(s) and the database(s) client library(ies) for efficient use