I discovered BRIN indexes fairly recently. You trade odd a bit of speed (data & query dependant, of course), but potentially gain a huge amount of disk space vs

I discovered BRIN indexes fairly recently. You trade odd a bit of speed (data & query dependant, of course), but potentially gain a huge amount of disk space vs B-Trees - the first time I created a BRIN index, I did a double take because I thought something must be wrong because the index was so small!