[bug#39258] [PATCH 0/4] Xapian for Guix package search

[zimoun]

Hi,

After a quick benchmark:

 a. It is faster. Between x2 and x3. Really?
 b. The xapian relevance should truncated and examined in more details.

--8<---------------cut here---------------start------------->8---
time guix search emacs | recsel -p name,relevance | head -n18
name: emacs
relevance: 33

name: emacs-with-editor
relevance: 19

name: emacs-restart-emacs
relevance: 19

name: emacs-epkg
relevance: 18

name: guile-emacs
relevance: 17

name: emacs-xwidgets
relevance: 17


real    0m1.530s
user    0m1.827s
sys     0m0.074s
--8<---------------cut here---------------end--------------->8---


--8<---------------cut here---------------start------------->8---
time /tmp/test/bin/guix search emacs | recsel -p name,relevance | head -n18
name: emacs-helm-pass
relevance: 5.0774748262821685

name: emacs-spark
relevance: 4.898640632723127

name: emacs-evil-smartparens
relevance: 4.898640632723127

name: emacs-howm
relevance: 4.8638448958830685

name: emacs-el-mock
relevance: 4.8638448958830685

name: emacs-strace-mode
relevance: 4.693676055650271


real    0m0.440s
user    0m0.482s
sys     0m0.058s
--8<---------------cut here---------------end--------------->8---


Here for example, Xapian does not return the package 'emacs' itself as
the first. And worse, it is not returned at all.
That's said, I do not know if it is really faster since:

--8<---------------cut here---------------start------------->8---
guix search emacs | recsel -C -P name | wc -l
829
--8<---------------cut here---------------end--------------->8---

and

--8<---------------cut here---------------start------------->8---
/tmp/test/bin/guix search emacs | recsel -C -P name | wc -l
10
--8<---------------cut here---------------end--------------->8---

Maybe I am doing a mistake.


Well, thank you Arun for the Xapian bindings which will improve the
searching experience. :-)
And now it needs some polishing.


All the best
simo