Comment by rswail

> Can I take two queries and squash them together in a reliable way? I feel like I end up with a lot of theme and variation in my queries, often involving optional filters.

That's essentially what SQL views do. Each view is a query and then you can treat it like a table and filter/join on it.

Of course, then the problem becomes whether or not the query planner can see through the view to the underlying tables to optimize correctly.