PostgreSQL EXPLAIN Output Explained
The article touched on some caveats but missed what I think is a big one - you really want to capture any detailed explains from environments as close to production as possible.  Different table statistics can cause the planner to go in wildly different directions and while faster is always better it is very easy to accidentally get caught up trying to sink a lot of effort into making a query more performant that was running slow due to thrashing in ram on a dev-box.<p>Explain (analyze at least - which you should always use) is a lot less theoretical than you might assume.  That can make it a bit more onerous to execute but it ends up adding a lot of value to the statistics when you gather them.<p>Oh also - query caching on postgres is a thing so if you're worried about performance from a cold state don't forget to clear caches before executing.  And if anyone has any good suggestions around tools to screw up table statistics I haven't found a good one that I like yet.