MongoDB vs. Redis vs. Cassandra for a fast-write, temporary row storage solution

Question

I\'m building a system that tracks and verifies ad impressions and clicks. This means that there are a lot of insert commands (about 90/second average, peaking at 250) and some

Answer 1

The problem with inserts into databases is that they usually require writing to a random block on disk for each insert. What you want is something that only writes to disk every 10 inserts or so, ideally to sequential blocks.

Flat files are good. Summary statistics (eg total hits per page) can be obtained from flat files in a scalable manner using merge-sorty map-reducy type algorithms. It's not too hard to roll your own.

SQLite now supports Write Ahead Logging, which may also provide adequate performance.