Re: File search progress: database review and question on triggers

[Pierre Neidhardt]

Arun Isaac <arunisaac@systemreboot.net> writes:

> sqlite insert statements can be very fast. sqlite.org claims 50000
> or...

I tried it, and got it down to... 30s!  Turns out that Guix already
provides `call-with-transaction' which I've used here.

So SQLite is back on the table.

>> I need to measure the time SQL takes for a regexp match.
>
> sqlite, by default, does not come with regexp support. You might have to
> load some external library. See
> https://www.sqlite.org/lang_expr.html#the_like_glob_regexp_and_match_operators
>
> --8<---------------cut here---------------start------------->8---
> The REGEXP operator is a special syntax for the regexp() user
> function. No regexp() user function is defined by default and so use of
> the REGEXP operator will normally result in an error message. If an
> application-defined SQL function named "regexp" is added at run-time,
> then the "X REGEXP Y" operator will be implemented as a call to
> "regexp(Y,X)".
> --8<---------------cut here---------------end--------------->8---

After more reading, I see the following options:

- Either we use the sqlite-pcre extension (which is not packaged in
  Guix).

- Or we extend guile-sqlite to add a binding to create_function
  (https://www.sqlite.org/appfunc.html).

- Or do you think SQLite patterns (using "%") would do for now?  As
  Mathieu pointed out, it's an unfortunate inconsistency with the rest of
  Guix.  But maybe regexp support can be added in a second stage.

Thoughts?

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

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