# FAQ

Here you will find some questions and answers

What about JOINs (known from SQL databases) ?
You can write database function. Please see :ref:join_like1. Just remember CodernityDB is not relational database.
Will it work on Jython ?
On 2.5 no, on 2.7 it should but currently it will not because of bug in Jython IO implementation. But currently Jython 2.7 is in alpha stage, so it will change in future.
How fast is CodernityDB ?
It's pretty fast. It can be said that you can insert even more than 55 000 records to Hash Index every second (see :ref:speed for more details)
Can I add index to existing DB ?
Yes you can, but you will need to reindex that index to have in it data that were in database already before you add that index. (see :ref:database_indexes for details)
What about tables or collections ?
Everything can be done through our Index mechanism see :ref:tables_colections_q.
How does it compare to MongoDB, CouchDB and other "big" NoSQL databases ?
It does not compare. Different purposes, different design, different use case. For some projects it makes sense to use CodernityDB instead of MongoDB, CouchDB and others, for some other not.
Why Python 3 is not supported ?
Python 3 introduced many incompatible changes. In case of CodernityDB having working version for 2.x and 3.x series in the same codebase without ugly hacks (big monkey-patching etc.) is almost impossible. If you're interested Python 3 version of CodernityDB contact us. Porting CodernityDB to Python 3.x is not hard. Python 3.x support in fact was never needed. That's why there is no support for it (yet?).
I want to contribute, what can I do?
Just fork and create pull request |bitbucket_link|.
I found a bug, where can I report it?