What I Learned Today (02/27/12)

There shouldn't be a day in your life when you don't learn something new.

I believe we all learn every day and just not always think about it. I thought I would start a daily digest of things I learned "today" to help me better remember it and to also share it with you as some may find it useful.

Some of it comes from the things I did while working on a problem in the office, some comes from reading or listening to other people, some comes from proof reading my son's homework. There's clearly different depth to the whole notion of "I learned it" so I by no means say that I am now an expert at the things I learned.

Too much "learned" already so with no further due today I have learned:

1. Groovy way of grabbing Maven dependencies via Grape and @Grab import annotations isn't searching in your local .m2 repo. You will need to make an explicit configuration in your .groovy/grapeConfig.xml to make it do a trip "home".
2. Cassandra's secondary index is a hash index so all you can ask it is the equality query. you can't do a range query on it and bitmap secondary indexes are not yet on the roadmap
3. The way you bulk load data into Cassandra is via building SSTable files directly and pushing them to the cluster. Nothing new really, all "databases" do direct datafiles writes for fast bulk inserts but here you literally create datafiles "increments"
4. Ruby has a define operator that you can use to find out if super is defined for the method you're in so you can do things like super if defined?(super). Pretty neat
5. Maven requires you to specify a version of your dependency and would otherwise refuse to build. There's a very popular question on SO why it's this way and how to make it go for the "latest" version.
6. There are 8 planets in our solar systems. There was 9 when I went to school and Pluto was since downgraded to be a dwarf planet with two more dwarfs discovered so it didn't feel lonely