Cache
Analysis of technologies that accelerate database management via caching. Related subjects include:
Membase simplifies name, goes GA
The company Northscale that makes the product Membase is now the company Membase that makes the product Membase. Good. Also, the product Membase has now gone GA.
I wrote back in August about Membase, and that covers most of what I think, with perhaps a couple of exceptions: Read more
| Categories: Basho and Riak, Cache, Couchbase, memcached, Memory-centric data management, NoSQL | 4 Comments |
More on NoSQL and HVSP (or OLRP)
Since posting last Wednesday morning that I’m looking into NoSQL and HVSP, I’ve had a lot of conversations, including with (among others):
- Dwight Merriman of 10gen (MongoDB)
- Damien Katz of Couchio (CouchDB)
- Matt Pfeil of Riptano (Cassandra)
- Todd Lipcon of Cloudera (HBase committer)
- Tony Falco of Basho (Riak)
- John Busch of Schooner
- Ori Herrnstadt of Akiban
Memcached-based company NorthScale launches
NorthScale, a start-up based around memcached, has just launched, two weeks after the Todd Hoff’s post arguing the MySQL/memcached combo is passe’. NorthScale wouldn’t necessarily argue with Todd, arguing that what you really should use instead is NorthScale’s combo of memcached and Membase, a memcached-like DBMS …
… or something like that. I don’t intend to write seriously about NorthScale until I have a better idea of what Membase is.
In the mean time,
- VentureBeat put up a solid post on NorthScale’s company history and so on
- Om Malik bought into the NorthScale memcached pitch
- TechCrunch has a low-quality post about NorthScale (although it wasn’t as error-riddled as the same author’s post about nStein, which Seth Grimes properly blasted)
| Categories: Cache, Clustering, Couchbase, memcached, NoSQL, Parallelization | Leave a Comment |
Notes on Sybase Adaptive Server Enterprise
It had been a very long time since I was remotely up to speed on Sybase’s main OLTP DBMS, Adaptive Server Enterprise (ASE). Raj Rathee, however, was kind enough to fill me in a few days ago. Highlights of our chat included: Read more
| Categories: Cache, In-memory DBMS, Memory-centric data management, Sybase | 1 Comment |
Two cornerstones of Oracle’s database hardware strategy
After several months of careful optimization, Oracle managed to pick the most inconvenient* day possible for me to get an Exadata update from Juan Loaiza. But the call itself was long and fascinating, with the two main takeaways being:
- Oracle thinks flash memory is the most important hardware technology of the decade, one that could lead to Oracle being “bumped off” if they don’t get it right.
- Juan believes the “bulk” of Oracle’s business will move over to Exadata-like technology over the next 5-10 years. Numbers-wise, this seems to be based more on Exadata being a platform for consolidating an enterprise’s many Oracle databases than it is on Exadata running a few Especially Big Honking Database management tasks.
And by the way, Oracle doesn’t make its storage-tier software available to run on anything than Oracle-designed boxes. At the moment, that means Exadata Versions 1 and 2. Since Exadata is by far Oracle’s best DBMS offering (at least in theory), that means Oracle’s best database offering only runs on specific Oracle-sold hardware platforms. Read more
Notes on the Oracle Database 11g Release 2 white paper
The Oracle Database 11g Release 2 white paper I cited a couple of weeks ago has evidently been edited, given that a phrase I quoted last month is no longer to be found. Anyhow, here are some quotes from and comments on what evidently is the latest version. Read more
What are the best choices for scaling Postgres?
March, 2011 edit: In its quaintness, this post is a reminder of just how fast Short Request Processing DBMS technology has been moving ahead. If I had to do it all over again, I’d suggest they use one of the high-performance MySQL options like dbShards, Schooner, or both together. I actually don’t know what they finally decided on in that area. (I do know that for analytic DBMS they chose Vertica.)
I have a client who wants to build a new application with peak update volume of several million transactions per hour. (Their base business is data mart outsourcing, but now they’re building update-heavy technology as well. ) They have a small budget. They’ve been a MySQL shop in the past, but would prefer to contract (not eliminate) their use of MySQL rather than expand it.
My client actually signed a deal for EnterpriseDB’s Postgres Plus Advanced Server and GridSQL, but unwound the transaction quickly. (They say EnterpriseDB was very gracious about the reversal.) There seem to have been two main reasons for the flip-flop. First, it seems that EnterpriseDB’s version of Postgres isn’t up to PostgreSQL’s 8.4 feature set yet, although EnterpriseDB’s timetable for catching up might have tolerable. But GridSQL apparently is further behind yet, with no timetable for up-to-date PostgreSQL compatibility. That was the dealbreaker.
The current base-case plan is to use generic open source PostgreSQL, with scale-out achieved via hand sharding, Hibernate, or … ??? Experience and thoughts along those lines would be much appreciated.
Another option for OLTP performance and scale-out is of course memory-centric options such as VoltDB or the Groovy SQL Switch. But this client’s database is terabyte-scale, so hardware costs could be an issue, as of course could be product maturity.
By the way, a large fraction of these updates will be actual changes, as opposed to new records, in case that matters. I expect that the schema being updated will be very simple — i.e., clearly simpler than in a classic order entry scenario.
CSQL: Yet another in-memory DBMS for caching
A few of you care about obscure in-memory DBMS products. Well, I was just e-mailed about another one, apparently called CSQL or CSQLcache. As of now, CSQL has a SourceForge website, a Wikipedia entry, and a blog.
One interesting thing on that blog is a taxonomy of caches — Level 1 cache, Level 2 cache, RAM, disk, etc., with some approximate figures for lookup times. Edit: However, Kevin Closson emailed me to say it’s way out of date. Stay tuned to his blog for more on the subject.
| Categories: Cache, In-memory DBMS, Memory-centric data management | 3 Comments |
Open source in-memory DBMS
I’ve gotten email about two different open source in-memory DBMS products/projects. I don’t know much about either, but in case you care, here are some pointers to more info.
First, the McObject guys — who also sell a relational in-memory product — have an object-oriented, apparently Java-centric product called Perst. They’ve sent over various press releases about same, the details of which didn’t make much of an impression on me. (Upon review, I see that one of the main improvements they cite in Perst 3.0 is that they added 38 pages of documentation.)
Second, I just got email about something called CSQL Cache. You can read more about CSQL Cache here, if you’re willing to navigate some fractured English. CSQL’s SourceForge page is here. My impression is that CSQL Cache is an in-memory DBMS focused on, you guessed it, caching. It definitely seems to talk SQL, but possibly its native data model is of some other kind (there are references both to “file-based” and “network”.)
| Categories: Cache, DBMS product categories, In-memory DBMS, McObject, Memory-centric data management, Object, OLTP, Open source | 5 Comments |
Optimizing WordPress database usage
There’s an amazingly long comment thread on Coding Horror about WordPress optimization. Key points and debates include:
- WordPress makes scads of database calls on every page. (20 is the supposed default number. That sounds a little high to me, but not wholly incredible.)
- Therefore one should use a caching plug-in. WP-Cache is the preferred one. WP-Super-Cache gets some votes as perhaps being even better.
- In theory the database cache should handle most of the problem. (After all, many of those database queries are the same for every page.) In practice, it often doesn’t, even if you use dedicated (as opposed to shared) web hosting.
- LAMP vs. Microsoft stack (uh-oh).
- Drupal vs. WordPress vs. Movable Type vs. Joomla vs. do-it-yourself (uh-oh too).
Another theme is — well, it’s WordPress “theme” design. Do you really need all those calls? The most dramatic example I can think of one I experienced soon after I started this blog. Some themes have the cool feature that, in the category list on the sidebar, there’s a count of the number of posts in the category. Each category. I love that feature, but its performance consequences are not pretty.
As previously noted, we’ll be doing an emergency site upgrade ASAP. Once we’re upgraded to WordPress 2.5, I hope to deploy a rich set of back-end plug-ins. One of the caching ones will be among them.
| Categories: About this blog, Application areas, Cache | 1 Comment |