Clearing a neo4j database

To completely clear a neo4j database run the following two commands:

start r=relationship(*) delete r

match a delete a

Note that these will still leave attributes in a database.

I am trying to decide between using neo4j as storage or using it as a qurery tool.

As a query tool you clean out the database and reload it before the set of queries.

As storage you need to maintain and upgrade the db.

Elixir – another language on the Erlang Runtime

Having read learning 7 languages in 7 weeks a couple of years ago I became impressed with erlang. The idea of using the actor model to create stable scalable, self healing systems is very compelling. The problem was the odd syntax that you had to put up with.

This week I found the follow up book 7 more languages in 7 weeks

This includes elixir a ruby like language that lives on the erlang vm. This looks to be a useful addition to the platform especially as it includes some string handling that Erlang is weak at.

One thing to note when installing elixir – you will need to upgrade your erlang version to 17 or 18. It requires a more recent version than was used when the first book came out.  Without this the command line tool iex will crash with a cryptic erlang error.