Collection counts in spec?

[moradology]

We don't mandate counts on searches for performance reasons (dynamic search results are of unpredictable size and anticipating returned object counts will not necessarily be easy in all API implementations) but it seems that such counts may be useful and very easy to implement at the level of collections. I've encountered some interest in this feature, what do others think?

[cholmes]

There is an extension, that was designed to work with static collections and API's, see https://github.com/stac-extensions/stats

I don't think any servers have yet implemented it, but I hope they do before too long.

[philvarner]

This would also be part of the

• Aggregation extension #38

e.g., you could run the same query with /search and /aggregate, and get either a page of results or the stats on the results

[philvarner]

Also related is

• Count Extension: endpoint /count to get only a count for a query #297

[philvarner]

These use cases are covered by:

• https://github.com/stac-api-extensions/aggregation
• Count Extension: endpoint /count to get only a count for a query stac-api-extensions/incubator#4