VoltDB and H-Store
Analysis of OLTP DBMS research project H-Store and its commercialization VoltDB. Related subjects include:
- Key H-Store researcher and VoltDB company founder Michael Stonebraker
- OLTP (OnLine Transaction Processing) database management
- Memory-centric data management
- Parallelization
- Vertica Systems, which is incubating VoltDB
The Boston Globe had an article on VoltDB
The Boston Globe article has more detail than Vertica and VoltDB have ever OKed me to put out, and some business details they’ve never given me.
| Categories: In-memory DBMS, Memory-centric data management, OLTP, Vertica Systems, VoltDB and H-Store | Leave a Comment |
NoSQL?
Eric Lai emailed today to ask what I thought about the NoSQL folks, and especially whether I thought their ideas were useful for enterprises in general, as opposed to just Web 2.0 companies. That was the first I heard of NoSQL, which seems to be a community discussing SQL alternatives popular among the cloud/big-web-company set, such as BigTable, Hadoop, Cassandra and so on. My short answers are:
- In most cases, no.
- Most of these technologies are designed for simple, high-volume OLTP (OnLine Transaction Processing.) Most large enterprises have an established way of doing OLTP, probably via relational database management systems. Why change?
- MapReduce is an exception, in that it’s designed for analytics. MapReduce may be useful for enterprises. But where it is, it probably should be integrated into an analytic DBMS.
- There’s one big countervailing factor to all these generalities — schema flexibility.
As for the longer form, let me start by noting that there are two main kinds of reason for not liking SQL. Read more
H-Store is now VoltDB
I’ve always honored more of an NDA about the H-Store project and its commercialization than I really felt obligated to, given how freely information was being bandied about to others. I’m still doing so. 
But I think I’ll at least say that the H-Store project is now named VoltDB. The VoltDB website names two individuals — Mike Stonebraker and Andy Palmer — both of whom are founders of Vertica. Job listings on the site are for field engineer and trainer, but not developer, so that suggests something about the project’s/product’s maturity level.
If you have an extreme OLTP need, you should talk to VoltDB. If you don’t have access to Mike or Andy directly, I can hook you up with a key VoltDB marketing/outreach guy. Price may not be as much of a barrier as you’d initially fear.
If anybody from VoltDB wants to be less cloak-and-daggery and say more in the comment thread, I’d be pleased.
And yes — an open-secret working name for H-Store/VoltDB was, for a while, “Horizontica.”
| Categories: In-memory DBMS, Memory-centric data management, OLTP, Vertica Systems, VoltDB and H-Store | 15 Comments |
Another round of discussion on in-memory OLTP data management
Oracle Exadata was pre-teased as “Extreme performance.” Some incorrect speculation shortly before the announcement focused on the possibility of OLTP without disk, which clearly would speed things up a lot. I interpret that in part as being wishful thinking.
The most compelling approach I’ve seen to that problem yet is H-Store, which however makes some radical architectural assumptions. One point I didn’t stress in my earlier posts, but which turned out to be a deal-breaker for one early tire-kicker, is that to use H-Store you have to be able to shoehorn each transaction into its own stored procedure. Depending on how intricate your logic is, that might make it hard to port an existing app to H-Store.
Even for new apps, it could get in the way of some things you might want to do, such as rule-based processing. And that could be a problem. A significant fraction of the highest-performance OLTP apps are customer-facing, and customer-facing apps are one of the biggest areas where rule-based processing comes into play.
| Categories: In-memory DBMS, Memory-centric data management, OLTP, VoltDB and H-Store | 3 Comments |
ObjectGrid versus H-Store
Billy Newport of IBM sees a lot of similarities between his app-server-based product ObjectGrid and H-Store. In both cases, constrained tree schemas are assumed, and OLTP performance goodness ensues. A couple of points I noted on a quick skim through his blog:
- He calls out RAM consumption as a challenge for this kind of architecture.
- He points out that it’s a big advantage to have data called and used in the same address space.
Being based in RAM is obviously a huge part of the H-Store scheme. But so is having transaction execution be close to the database.
IBM now has both ObjectGrid and a memory-centric DBMS (solidDB) that they’ve been using as a front end for DBMS. Integration of the two could be pretty interesting.
| Categories: Cache, IBM and DB2, Memory-centric data management, OLTP, solidDB, Theory and architecture, VoltDB and H-Store | Leave a Comment |
The architectural assumptions of H-Store
I wrote yesterday about the H-Store project, the latest from the team of researchers who also brought us C-Store and its commercialization Vertica. H-Store is designed to drastically improve efficiency in OLTP database processing, in two ways. First, it puts everything in RAM. Second, it tries to gain an additional order of magnitude on in-memory performance versus today’s DBMS designs by, for example, taking a very different approach to ensuring ACID compliance.
Today I had the chance to talk with two more of the H-Store researchers, Sam Madden and Daniel Abadi. Read more
| Categories: Database diversity, In-memory DBMS, Memory-centric data management, OLTP, VoltDB and H-Store | 5 Comments |
Mike Stonebraker calls for the complete destruction of the old DBMS order
Last week, Dan Weinreb tipped me off to something very cool: Mike Stonebraker and a group of MIT/Brown/Yale colleagues are calling for a complete rewrite of OLTP DBMS. And they have a plan for how to do it, called H-Store, as per a paper and an associated slide presentation.