[bug#39258] Faster guix search using an sqlite cache

[zimoun <zimon.toutoune@gmail.com>]

Hi Arun,

Thank you for the patch!
Cool! :-)

I have not tested it yet. Sorry.


On Thu, 23 Jan 2020 at 20:53, Arun Isaac <arunisaac@systemreboot.net> wrote:

> At the moment, I am having some difficulty populating the sqlite
> database. generate-package-cache populates the database correctly when
> invoked from a normal guile REPL using geiser, but fails to do so when
> run by the guix daemon during guix pull.

[...]

> On examining package-cache.sqlite, I find that no records have been
> written. And, there is a lingering journal file that shouldn't be
> there. For some reason, populating the sqlite database does not work
> with guix pull. sqlite probably crashes and leaves the journal file.

Hum? weird...
Is it possible that a module is loaded when Guile repl is used and not
with Guix pull?
What about "guix repl"?


> If I try to populate the database with each package record being
> inserted in its own transaction, at least some of the insertions

You mean 'commit' the database after each insertion, right?


> work. But the journal file still lingers. My unverified guess is that
> everything except the last transaction was successful.

And this does not happen with the repl, right?


> Any ideas what's going on?

I have no idea.
Weird.

What about adding 'last-insert-row-id' from 'guix/store/database.scm'?
I mean without really understanding and just grepping
'sqlite-finalize' spots that 'last-insert-row-id' seems often around.
:-)


> Also, inserting each package in its own transaction is ridiculously slow
> and so that is out of the question. See https://www.sqlite.org/faq.html#q19

Agree that it is not an option. :-)


Otherwise, 'list->string' is defined twice. And the first one is not
necessary, I guess.
The docstring of 'cache-lookup' is not coherent anymore. :-)


Cheers,
simon