AT ORACLE: Interview
Building a Better Database MachineBy Tom Haunert
The Sun Oracle Database Machine is the first for OLTP and better for all applications.
Juan Loaiza, senior vice president of systems technology at Oracle, sat down with Tom Haunert, Oracle Magazine editor in chief, to talk about Oracle Exadata V2 and the Sun Oracle Database Machine. The following is an excerpt from that interview. Download a podcast of the full interview at oracle.com/magcasts.
Oracle Magazine: What are the key technology innovations in Oracle Exadata V2 and the Sun Oracle Database Machine?
Loaiza: There are three key innovations in Oracle Exadata V2. The first is the intelligent Oracle Exadata storage (which we introduced in Oracle Exadata V1) that is deployed in a grid scale-out architecture using InfiniBand networking. So it’s very high performance with very high-speed networking.
Second, we’ve introduced a technology called Hybrid Columnar Compression, which provides much better compression than we or anyone else has achieved before. We think it’s going to have dramatic benefits for very large databases.
Third, we’ve incorporated Flash technology into the Sun Oracle Database Machine, and we’ve done it in an innovative way that’s high performance, easy to use, low cost, and highly available.
Oracle Magazine: What’s new in intelligent storage in Oracle Exadata V2?
Loaiza: Intelligent storage was the big innovation in Oracle Exadata V1, and we’ve enhanced it in Oracle Exadata V2. We’ve done three things to avoid storage bottlenecks. First, we do query processing inside storage. Second, we went away from the monolithic storage architecture to a scale-out storage architecture. Our storage is made from modular building blocks that are basically servers with disks in them. Third, we use an InfiniBand network that runs at 40Gb/second. That’s key to getting lots of data from storage into the database servers very quickly, especially as we bring Flash into the picture.
Oracle Magazine: How does Oracle’s Hybrid Columnar Compression work?
Loaiza: With Hybrid Columnar Compression, we transparently reorganize the data into a column-oriented format to achieve much better compression. With our previous generations of compression, we usually achieved 2 to 4 times compression on user data. With Hybrid Columnar Compression, we typically achieve 10 times or more compression.
We are starting to get the early results back from customers with very large databases, and they are amazing. For example, a telecom customer that tried Hybrid Columnar Compression using call data records, which traditionally don’t compress very well, is achieving over 6 times compression. This is much higher compression than we’ve ever seen before with call data records.
We have two modes for Hybrid Columnar Compression. We have a very fast mode called compress for query , and we have a mode that optimizes space called compress for archive . A very large financial company has achieved 19 times compression with compress for query mode, which is a tremendous compression rate. And a scientific customer saw 70 times compression with compress for archive mode.
Oracle Magazine: What’s new and innovative about the Flash technology in Oracle Exadata V2?
Loaiza: In Oracle Exadata V2, we’ve incorporated a new technology from Sun called FlashFire technology in every storage server.
Up to now, Flash had been introduced as kind of a disk replacement. It included a disk-drive interface and sat behind a disk controller, but inside it was actually a bunch of Flash chips. That was the first generation of Flash technology, and it worked pretty well. But having Flash look like a disk drive and sit behind a disk controller actually limits the performance quite a bit.
With FlashFire, Sun has introduced a technology where the Flash memory actually sits on a PCI card that goes directly into the motherboard of the servers. That’s what we’re using in our Oracle Exadata storage, and it’s much, much faster than using Flash as a disk drive. Imagine putting DRAM into a disk form factor and sitting it behind the disk controller. You’re going to lose a lot of the performance of that DRAM. Flash is a lot more like DRAM than like a disk drive. Flash is a semiconductor technology, and it’s much better to introduce it closer to the processors.
We’re primarily using the Flash in our Oracle Exadata Storage Servers as a cache in front of the disk drives. We have 5TB of Flash in a one-rack Sun Oracle Database Machine, and we automatically manage which data goes on disk and which data goes on Flash. And as data becomes active, we’ll move it automatically into Flash so that subsequent accesses will get the performance of Flash.
Oracle Magazine: How can OLTP [online transaction processing] customers benefit from Oracle Exadata V2?
Loaiza: In Oracle Exadata V2, we’ve introduced support for OLTP, so OLTP customers get great benefits from the intelligent storage grid. We’re able to offload query operations for OLTP just like we do for data warehousing.
One of the unique features of Oracle technology is that we’re able to run very complex and sophisticated OLTP applications in a scale-out grid infrastructure using Oracle RAC [Oracle Real Application Clusters]. This includes applications such as Siebel, PeopleSoft, and Oracle E-Business Suite. The other key OLTP feature is the use of Flash in Oracle Exadata V2 to greatly speed up OLTP. With the Flash that we have in a one-rack Sun Oracle Database Machine, we can run at more than a million I/Os per second, which is a rate that has never been seen before. Before Oracle Exadata V2, it would take around 100 racks of storage to achieve that kind of performance, and it would cost millions and millions of dollars.
Oracle Magazine: How do storage and performance compare between Oracle Exadata V1 and Oracle Exadata V2?
Loaiza: In Oracle Exadata V1 we had the intelligent, scale-out storage grid, and we were able to run queries at a rate of 14GB/second off disk. That’s 5 to 10 times faster than other storage devices that were much bigger than ours. In Oracle Exadata V2 the disk performance is 50 percent faster than in Oracle Exadata V1. But more importantly, the compression technologies are a key part of the data-warehousing story in Oracle Exadata V2. If we achieve 10 times compression with our Hybrid Columnar Compression technology, the customers’ very large data warehouses—whether they’re 1TB, 10TB, 50TB, or 100TB, can be shrunk in size. This greatly improves performance. Also, it’s very cumbersome to do backup or restore or reorganization of the data on these extremely large systems. If you can shrink the size by a factor of 10, it makes it an order of magnitude easier to manage and also gives much lower cost and much higher performance.