[bug#33210] Cuirass: Use a SQLite in single-thread mode

["Clément Lassieur" <clement@lassieur.org>]

Ludovic Courtès <ludo@gnu.org> writes:

> Hello,
>
> Clément Lassieur <clement@lassieur.org> skribis:
>
>> These patches are supposed to slightly improve Cuirass' performances,
>> because it doesn't use the multi-threading features.
>
> Did you notice a measurable difference?

I haven't done any measurement yet, but according to the SQLite
documentation:

    Setting -DSQLITE_THREADSAFE=0 causes all of the mutex and
    thread-safety logic in SQLite to be omitted. This is the single
    compile-time option that makes the most difference in optimizing the
    performance of SQLite.

So even if the optimization is small, it's the option that has the
biggest impact on performance.

> We could do it, but IMO that should be a last resort because I’d expect
> it to be a micro-optimization.

Lots of micro-optimizations lead to an overall faster application ;-).
And this one doesn't make the code more complicated.  To me it's just a
bonus.

[1]: https://www.sqlite.org/compile.html