On 26th of March, Heikki Linnakangas committed patch: Add support for index-only scans in GiST. This adds a new GiST opclass method, 'fetch', which is used to reconstruct the original Datum from the value stored in the index. Also, the 'canreturn' index AM interface ...

Last time I wrote about what explain output shows. Now I'd like to talk more about various types of "nodes" / operations that you might see in explain plans.