Sorry for the delay.

I've pushed a commit which adds the synopsis and the description to the
database.

0127cfa5d0898222257a716bf7b0a167f31cc6dd

The quite surprising result is that these new details only cost 1 MiB extra!

I can then search packages and it's super fast:

--8<---------------cut here---------------start------------->8---
> ,time (search-package "org" "equival") 
$51 = (("emacs-org-contrib"))
;; 0.002930s real time, 0.002925s run time.  0.000000s spent in GC.
--8<---------------cut here---------------end--------------->8---

My local database only includes the store items, that is to say some
1800 items, but even with the 15000 packages the search would not be
impacted by much.  The size might grow by some 10 MiB though, but that's
reasonable and it compresses very well (down to 6-7 MiB in zstd).

It seems to me that Simon had a very good hunch: the filesearch
implementation could fix the slow search issue for free.

Thoughts?

-- 
Pierre Neidhardt
https://ambrevar.xyz/