Database solution for 200million writes/day, monthly summarization queries

I'm looking for help deciding on which database system to use. (I've been googling and reading for the past few hours; it now seems worthwhile to ask for help from someone with firsthand knowledge.)

I need to log around 200 million rows (or more) per 8 hour workday to a database, then perform weekly/monthly/yearly summary queries on that data. The summary queries would be for co开发者_StackOverflowllecting data for things like billing statements, eg. "How many transactions of type A did each user run this month?" (could be more complex, but that's the general idea).

I can spread the database amongst several machines, as necessary, but I don't think I can take old data offline. I'll definitely need to be able to query a month's worth of data, maybe a year. These queries would be for my own use, and wouldn't need to be generated in real-time for an end-user (they could run overnight, if needed).

Does anyone have any suggestions as to which databases would be a good fit?

P.S. Cassandra looks like it would have no problem handling the writes, but what about the huge monthly table scans? Is anyone familiar with Cassandra/Hadoop MapReduce performance?

I'm working on a very similar process at the present (a web domain crawlling database) with the same significant transaction rates.

At these ingest rates, it is critical to get the storage layer right first. You're going to be looking at several machines connecting to the storage in a SAN cluster. A singe database server can support millions of writes a day, it's the amount of CPU used per "write" and the speed that the writes can be commited.

(Network performance also often is an early bottleneck)

With clever partitioning, you can reduce the effort required to summarise the data. You don't say how up-to-date the summaries need to be, and this is critical. I would try to push back from "realtime" and suggest overnight (or if you can get away with it monthly) summary calculations.

Finally, we're using a 2 CPU 4GB RAM Windows 2003 virtual SQL Server 2005 and a single CPU 1GB RAM IIS Webserver as our test system and we can ingest 20 million records in a 10 hour period (and the storage is RAID 5 on a shared SAN). We get ingest rates upto 160 records per second batched in blocks of 40 records per network round trip.

Cassandra + Hadoop does sound like a good fit for you. 200M/8h is 7000/s, which a single Cassandra node could handle easily, and it sounds like your aggregation stuff would be simple to do with map/reduce (or higher-level Pig).

Greenplum or Teradata will be a good option. These databases are MPP and can handle peta-scale data. Greenplum is a distributed PostgreSQL db and also has it own mapreduce. While Hadoop may solve your storage problem but it wouldn't be helpful for performing summary queries on your data.