PicoLisp uses normal files for blobs as you know, but I never felt they are too slow
What SQLite does seems more like +Swap in PicoLisp
there we have also no separate open/close
ah, maybe it is mainly about non-linux-OSes
HN comment says "It gets weird when you throw Linux in the mix - open/close are extremely cheap on Linux, to the point of being free - at least used to be before Spectre and Meltdown and what not. So on Linux doing n more open/closes isn't much different than doing a single pair if n is not humongous and the program is doing other things besides just open close."