Re: New package: resist!

[Óscar Fuentes]

Qiantan Hong <qhong@mit.edu> writes:

>> Does this package require the entire store to be loaded into memory in order 
>> for a single value to be looked up or stored?
>> 
>> It looks like it does (based on reading `kv-get', etc), but I might be 
>> missing something.
>
> It is. According to my benchmark I don’t think this is a problem
> for most Emacs use cases (it loads 10k entry within 0.03s,
> I’ve tested longer list).

Was it with a cold disk cache? SSD or HDD? :-)

I'm afraid that you are focusing too much on a single metric.

You don't mention how large is each record, but anyway 10k records is a
tiny number for any serious database application. And then we have
memory pressure: apart from raw RAM usage, IIRC Emacs' garbage collector
traverses live objects, which means that Emacs becomes slower as the
info it holds grows. Then we have the persistence requirement: if we
want frequent, persistent updates to the database, having to write the
database's entire content each time we want to persist a change is
unacceptable. Then, if we want concurrent access from multiple sessions
(which itself requires some level of support for atomic operations) your
approach of reading and saving a big file becomes unfeasible in
practice, unless for tiny databases.

Don't get me wrong, I'm also worried about introducing sqlite support in
core. I'm afraid that it will be misused, a solution that creates
problems, so to speak, but it is undeniable that there are reasonable
uses for a proper database on Emacs.