There was very interesting presentation by one professor. I'm not sure about what university, but he seemed to know his work.<p>He talked about how databse world is about to change. ACID is really expensive in terms of resources, and so are the more difficult things about relational schema (foreign keys, checks, etc). And architecture of classic RDBMSes is pretty wasteful -- they use on-disk format but cache it in memory.<p>He talked about how there are basically three new paths for DBMSes to follow.
1) Some drop the restrictions to become faster. This is the NoSql stuff, because you don't really need ACID for writing to Facebook wall.<p>This is called NoSql database.<p>2) OLAP, in data warehousing, the usual way to do things is that you load ridiculous amount of data into database, and then run analytical queries, that tend to heavily use aggregation and sometimes use just few dimmensions, while the DWH data tend to be pretty wide.<p>For this, column store makes perfect sense. It is not very quick on writes, but it can do very fast aggregation and selection of just few columns.<p>This is called Column store.<p>3) In OLTP, you need throughtput, but the question is, how big are your data, and how fast do they grow? Because RAM tends to get bigger exponentially, while how many customers you have will probably grow linearly or maybe fuster, but not much. So your data could fit into memory, now, or in future.<p>This allows you to make very fast database. All you need to do is to switch the architecture to memory-based, store data in memory format in memory and on disk. You don't read the disk, you just use it to store the data on shutdown.<p>This is called Main memory database.<p>No, that was the presentation. It was awesome, and if someone can find it, please give us a link! My search-fu was not strong enouhg.<p>...<p>What interests me is that we have NoSql databases for some time already, and we have at least one huge (are very expensive) column store: Teradata. But this seems to be first actual Main memory database.<p>My dream would be to switch Postgres to main memory or column store mode, but I guess that's not happening very soon :)