I’ve also experiemented with putting indexes on Ramdisk (partly for same reason, writes on SSD degrade its lifespan)
It worked fine. Particully for indexes that will be regually rebuilt, (ie rebuilt on boot anyway)
Its not terribly efficent memory wise, as manticore lods much of the index into memory anyway, and as far as could see the ramdisk was cached in the OS level ‘page cache’ anyway, perhaps even by manticore mmapping too.
… so the index is multiple times in memory.
… in general using a RT index (even just for the delta, with a RAM chunk big enough that entirely in memory) is more efficent, but can be more work to setup if ‘used’ to workin with indexer.
… In theory can pipe indexer --dump-rows (or perhaps --print-rt) to searchd to (re)build a delta index (into a RAM chunk!) - but never tried in practice.
Would give you the ‘small’ index held entirely in RAM, once. And it can be rebuilt easily (although would need to contrive the ‘atomic’ switch, traditionally get with ‘–rotate’.