Very interesting. It certainly shows the potential a replacement of the very old ELF could offer. It even looks very plausibly doable. Now it just needs to get all distros on board. :P

I'm not sure I understood the jump from single file SELF to userland-wide.

Can the SQL be precompiled into binary for faster lookups? I imagine there's not much variance in the standard queries. That could offer some speedup, skipping the query analyzer/tokenizer/interpreter.

I'm not sure I followed how the LD_PRELOAD equivalent works now.

What are disadvantages of using SELF? (Assuming a full OS switch to SELF. Mixed is always additional burden.)