Data warehousing
Analysis of issues in data warehousing, with extensive coverage of database management systems and data warehouse appliances that are optimized to query large volumes of data. Related subjects include:
Teradata Unity and the idea of active-active data warehouse replication
Teradata is having its annual conference, Teradata Partners, at the same time as Oracle OpenWorld this week. That made it an easy decision for Teradata to preannounce its big news, Teradata Columnar and the rest of Teradata 14. But of course it held some stuff back, notably Teradata Unity, which is the name chosen for replication technology based on Teradata’s Xkoto acquisition.
The core mission of Teradata Unity is asynchronous, near-real-time replication across Teradata systems. The point of “asynchronous” is performance. The point of “near-real-time” is that it Teradata Unity can be used for high availability and disaster recovery, and further can be used to allow real work on HA and DR database copies. Teradata Unity works request-at-a-time, which limits performance somewhat;* Unity has a lock manager that makes sure updates are applied in the same order on all copies, in cases where locks are needed at all.
| Categories: Data warehousing, Teradata | 2 Comments |
Highlights of a busy news week
I put up 14 posts over the past week, so perhaps you haven’t had a chance yet to read them all. 🙂 Highlights included:
- My most important post of the week was a general guide to IT vendor strategy. That one has already spawned discussion at many companies, from the tiny to the multi-billion-dollar.
- The best comment thread of the week was probably on my post about scale-out relational OLTP choices, in which people discussed the merits of various particular alternatives.
- I recommended that people strongly consider attending XLDB 5 in Menlo Park on October 18-19.
Most of the posts, however, were reactions to news events. In particular:
- Teradata announced that Teradata 14 will be hybrid-columnar, more in Vertica’s way than in Greenplum’s or Aster Data’s. (Pay no attention to the Wall Street Journal’s apparent belief that no other analytic DBMS is hybrid-columnar at all.)
- Aster announced the unsurprising news that there will be a Teradata Aster appliance. Also, Aster talked about greater analytic flexibility in the forthcoming Aster 5.0.
- With Oracle OpenWorld coming up, Oracle decided to get some of its announcing out of the way early. In particular, it announced the Oracle Database Appliance, which is small-business-friendly hardware for running the Oracle DBMS. However, the Oracle Database Appliance doesn’t seem to do much about the complexity of running the Oracle DBMS software.
- In a catch-all Hadoop post, I noted that:
- Oracle has now clearly said it has a Hadoop appliance coming, no doubt next week at OpenWorld.
- I still can’t see why Hadoop appliances would succeed, but a lot of smart folks seem to disagree with me.
- Greenplum announced what looks like a nice but unimportant little product upgrade.
- It’s a really good thing that previously reported plans to revamp Hadoop are underway.
- DataStax announced that it really is a Cassandra company after all. Pay no attention to previous marketing that seemed to put DataStax in the same Hadoop-alternative category as, say, MapR.
- Ingres has changed its name to Actian. The announcement seems like a confession that Ingres and VectorWise are going nowhere.
| Categories: Actian and Ingres, Aster Data, Data warehousing, DataStax, Greenplum, Hadoop, Teradata, VectorWise | Leave a Comment |
Workload management and RAM
Closing out my recent round of Teradata-related posts, here’s a little anomaly:
- Teradata is proud that Teradata 14’s workload management now explicitly manages I/O, to go with Teradata’s long-standing management of CPU. Teradata’s WLM still does not explicitly manage RAM.
- Aster is proud that Aster 5’s workload management now explicitly manages RAM, to go along with the WLM capabilities Aster has had for a while managing CPU and I/O. Aster’s Tasso Argyros believes this is an important capability, at least in some edge cases.
- Mike Pilcher of SAND emailed me that SAND’s WLM capabilities to explicitly manage CPU, I/O, and RAM are very well-received by the marketplace.
| Categories: Aster Data, Data warehousing, SAND Technology, Teradata, Workload management | 4 Comments |
Hybrid-columnar soundbites
Busy couple of days talking with reporters. A few notes on hybrid-columnar analytic DBMS, all backed up by yesterday’s post on Teradata columnar:
- Oracle does not actually offer columnar I/O; the other three systems do. But see the “I won’t be surprised” part in yesterday’s Teradata post.
- Aster does not offer columnar compression; the other three do.
- EMC Greenplum and Teradata offer different kinds of ways to mix column and row storage in the same table; each has its advantages.
- Teradata generally has a more mature and capable offering than EMC Greenplum, for most purposes, whichever way you choose to organize your tables.
Edit: The Wall Street Journal got this wrong, writing that Teradata was the first-ever hybrid columnar system. Specifically, they wrote
While columnar technology has been around for years, Teradata says its product is unique because it allows users to include both columns and rows in the same database.
Googling on “Teradata To Unveil New Analytics Product To Speed Business Adoption” might get you around the paywall to see the offending piece.
| Categories: Aster Data, Columnar database management, Data warehousing, Database compression, Greenplum, Teradata | 2 Comments |
Aster Database Release 5 and Teradata Aster appliance
It was obviously just a matter of time before there would be an Aster appliance from Teradata and some tuned bidirectional Teradata-Aster connectivity. These have now been announced. I didn’t notice anything particularly surprising in the details of either. About the biggest excitement is that Aster is traditionally a Red Hat shop, but for the purposes of appliance delivery has now embraced SUSE Linux.
Along with the announcements comes updated positioning such as:
- Better SQL than the MapReduce alternatives have.
- Better MapReduce than the SQL alternatives have.
- Easy(ier) way to do complex analytics on multi-structured data. (Aster has embraced that term.)
and of course
- Now also with Teradata’s beautifully engineered hardware and system management software!
| Categories: Aster Data, Data warehouse appliances, Data warehousing, Predictive modeling and advanced analytics, Teradata, Workload management | Leave a Comment |
Teradata Columnar and Teradata 14 compression
Teradata is pre-announcing Teradata 14, for delivery by the end of this year, where by “Teradata 14” I mean the latest version of the DBMS that drives the classic Teradata product line. Teradata 14’s flagship feature is Teradata Columnar, a hybrid-columnar offering that follows in the footsteps of Greenplum (now part of EMC) and Aster Data (now part of Teradata).
The basic idea of Teradata Columnar is:
- Each table can be stored in Teradata in row format, column format, or a mix.
- You can do almost anything with a Teradata columnar table that you can do with a row-based one.
- If you choose column storage, you also get some new compression choices.
| Categories: Archiving and information preservation, Columnar database management, Data warehousing, Database compression, Oracle, Rainstor, Teradata | 7 Comments |
XLDB: The one conference I like to attend
I’m not a big fan of conferences, but I really like XLDB. Last year I got a lot out of XLDB, even though I couldn’t stay long (my elder care issues were in full swing). The year before I attended the whole thing — in Lyon, France, no less — and learned a lot more. This year’s XLDB conference is at SLAC — the organization formerly known as the Stanford Linear Accelerator Center — on Sand Hill Road in Menlo Park, October 18-19. As of right now, I plan to be there, at least on the first day. XLDB’s agenda and registration details (inexpensive) can be found on the XLDB conference website.
The only reason I wouldn’t go is if that turned out to be a lousy week for me to travel to California.
The people who go XLDB tend to be really smart — either research scientists, hardcore database technologists, or others who can hold their own with those folks. Audience participation can be intense; the most talkative members I can recall were Mike Stonebraker, Martin Kersten, Michael McIntire, and myself. Even the vendor folks tend to the smart — past examples include Stephen Brobst, Jeff Hammerbacher, Luke Lonergan, and IBM Fellow Laura Haas. When we had a datageek bash on my last trip to the SF area, several guys said they were planning to attend XLDB as well.
XLDB stands for eXtremely Large DataBases, and those are indeed what gets talked about there. Read more
| Categories: Data warehousing, Predictive modeling and advanced analytics, Scientific research | 5 Comments |
Are there any remaining reasons to put new OLTP applications on disk?
Once again, I’m working with an OLTP SaaS vendor client on the architecture for their next-generation system. Parameters include:
- 100s of gigabytes of data at first, growing to >1 terabyte over time.
- High peak loads.
- Public cloud portability (but they have private data centers they can use today).
- Simple database design — not a lot of tables, not a lot of columns, not a lot of joins, and everything can be distributed on the same customer_ID key.
- Stream the data to a data warehouse, that will grow to a few terabytes. (Keeping only one year of OLTP data online actually makes sense in this application, but of course everything should go into the DW.)
So I’m leaning to saying: Read more
“Big data” has jumped the shark
I frequently observe that no market categorization is ever precise and, in particular, that bad jargon drives out good. But when it comes to “big data” or “big data analytics”, matters are worse yet. The definitive shark-jumping moment may be Forrester Research’s Brian Hopkins’ claim that:
… typical data warehouse appliances, even if they are petascale and parallel, [are] NOT big data solutions.
Nonsense almost as bad can be found in other venues.
Forrester seems to claim that “big data” is characterized by Volume, Velocity, Variety, and Variability. Others, less alliteratively-inclined, might put Complexity in the mix. So far, so good; after all, much of what people call “big data” is collections of disparate data streams, all collected somewhere in a big bit bucket. But when people start defining “big data” to include Variety and/or Variability, they’ve gone too far.
Aster Data business trends
Last month, I reviewed with the Aster Data folks which markets they were targeting and selling into, subsequent to acquisition by their new orange overlords. The answers aren’t what they used to be. Aster no longer focuses much on what it used to call frontline (i.e., low-latency, operational) applications; those are of course a key strength for Teradata. Rather, Aster focuses on investigative analytics — they’ve long endorsed my use of the term — and on the batch run/scoring kinds of applications that inform operational systems.