
Show HN: Pisa – Full Text Search Engine Written in C++ - amallia
https://github.com/pisa-engine/pisa
======
rubyn00bie
Ugh, I hate it when readme's have zero useful information; and literally only
a way to cite them as a source... this is a big problem with C++ libraries. I
100% think the author(s) deserve credit for their work, and I'm sure it's
brilliant, but I'll never use your work if I don't know what it does.

How does this compare to anything other than being fast? Why should I use it?
Can't you include a few examples, use cases, or reasons why it exists? Is it
in memory, distributed, on disk... when is it fast? Does it have a binary I
can run?

[clicks around documentation site]

... oh shit there is a binary of something, maybe multiple... how about
showing those on the readme? Or maybe talk about what algorithms are actually
implemented instead of just saying lots of them are.

~~~
PisaSheeya
I had the same problem. I really wanted to like this project, but I found it
hard to get a handle on what their goal is. Performant, c++17, open source, IR
tools sounds great to me. But.. how does someone use this? Are they a parallel
to Lucene? ElasticSearch? Grep?

Talking about scale would help a lot here. What's the largest dataset they've
indexed? Do they shard across multiple nodes? etc.

I found they had a research paper about PISA at OSIRRC (a replicability
challenge for ir?) last year with some details. You can get the paper and
slides off the conference site:

[https://osirrc.github.io/osirrc2019/](https://osirrc.github.io/osirrc2019/)

They have run the dataset on things like ClueWeb12 (1.5TB web), but the paper
was about replicable search and lacked performance comparisons to other
systems. It's hard to call yourself performant unless you show you're at least
as good as other implementations.

------
BubRoss
The only mention of a benchmark I see is an issue raised over a year ago, so I
wonder what they are basing this claim on.

~~~
epr
It is quite confusing when projects advertise that they have best-in-class
performance then don't provide benchmark results in the readme or
documentation. This may be an extreme example of that.

~~~
b52_
Where do they claim to be best in class? I don't seem to see that anywhere.

------
rozim
Would be nice to see it compared with Xapian as Xapian has been around for a
long time.

[https://xapian.org/](https://xapian.org/)

------
ddorian43
There is also vespa.ai proton search-core in c++
[https://docs.vespa.ai/documentation/proton.html](https://docs.vespa.ai/documentation/proton.html)

------
igammarays
I want someone to use one of these libraries to build a local-desktop-offline
personal search engine which only crawls sources I select, including my
personal emails and browsing history.

~~~
syspec
Finder on OSX meets that criteria

~~~
jdc
Now if only it would index the _actual web pages_ of the browser history.

~~~
SanchoPanda
Recoll does this.

~~~
ternaryoperator
That looks like a really cool tool. Thanks for mentioning it!

------
prtaylor
What makes it specific to academia? Can't it be used as a general purpose
search?

------
skyde
nice I didn’t know about this project and it’s using my implementation of
VarIntG8IU codec.

I will give it a try.

~~~
amallia
Maxime Caron?

