One of the more common SAP complaints heard at the water cooler is that SAP Business Warehouse (BW) queries are
taking too long.
When it comes to performance, BW hasn't really cut it as a traditional data warehouse. For example, a solid data warehouse has a multi-dimensional data model. However, BW is a flat, relational database. Therefore, BW doesn't scale to accommodate large data sets, and despite well-entrenched tuning techniques, performance has always been a pain point, according to Justin Burmeister, a longtime Basis administrator.
SAP's answer is the Business Warehouse Accelerator (BWA). By integrating the TREX search engine with BW, indexing all of the fact tables and putting it all in-memory, SAP created a brilliant architecture, Burmeister said. Query performance in BW is reduced from several minutes to seconds. Queries aren't performed on insufficient subsets of data. System performance isn't negatively affected. Users are wildly happy.
But then the bill comes – along with the nagging feeling of getting charged for something SAP perhaps should have fixed in the first place and the frustration of seeing obvious ways the whole project could be cheaper.
"On the Basis team, we're heroes, taking the 20-minute queries down to two seconds (with the BWA)," Burmeister said, adding that while SAP has recognized the popularity of the BWA, it responded with a "ludicrous" pricing model.
"The licensing model is a total boondoggle," he said. "To me, this is a workaround to fundamental architecture flaws in BW, under the pretext of 'certified hardware/software integrated solutions,' serving as a cash cow for SAP and its hardware partners. You shouldn't have to do this in the first place."
Why does the BWA cost so much?
Cost is the chief complaint with the BWA, and several customers interviewed blamed the way BWA is being sold.
A BWA is sold in two parts: Customers buy the hardware package from their choice of hardware partner, and SAP sells and licenses the software. The software is already loaded onto the hardware, and the hardware is preconfigured to plug into the customers' environment like an appliance – with the goal of everything working out-of-the-box, according to SAP.
IBM, HP, Fujitsu, Dell, Cisco, Sun/Oracle, and Teradata are the "key" BWA partners, according to SAP.
The biggest expense is the hardware, which can't be shared with any other application. SAP's list price for the software is around $50,000, according to Forrester Research's Boris Evelson, principal analyst with the Cambridge, Mass.-based firm. The average price for the hardware is around $200,000, according to Forrester.
SAP acknowledged customer dissatisfaction with the pricing model and said in an email response, "We understand there has been some discussion about the cost of the product, and we're constantly reviewing our pricing and deployment flexibility as we improve BWA."
Users see some obvious ways the cost of a BWA can be brought down.
One, for example, is being able to install it on their own. Customers are discouraged from installing the BWA themselves, said Tony De Thomasis, NetWeaver Technician at Australia Post, the Austalian postal service. Customers who try to do so are prompted with this message on the main BWA installation splash-screen, "Support can only be granted for installations performed by these vendors…"
"I would much prefer to stand up my own infrastructure and run the BWA the same way I run my NetWeaver Enterprise Search instance," De Thomasis said in an email interview.
SAP should allow customers to build their own accelerators using their own hardware, integrating the TREX search engine software with BW themselves, Burmeister said. One large customer he worked with was ready to spend $750,000 on blade hardware that would have cost $90,000 to $120,000 had it not been purchased as part of a BWA sale.
Still, customers are left with a difficult decision – one in which the benefits of BWA are tough to ignore.
"BWA has become quite a big decision for BW customers," Gartner Research vice president Kurt Schlegel said in an email. "They really need the performance boost it provides, but it is quite expensive and SAP is not discounting. I wouldn't expect SAP to soften their stance, as they are making too much money from the BWA."
Take Australia Post, for example. The organization, which runs 80 SAP instances, recently partnered with IBM on a BWA pilot program. Query performance in the BW 7.01 is acceptable now, De Thomasis said. But with a 1.1 terabyte (TB) database growing at approximately 200 gigabytes per month, query runtime will become longer and overall system performance will degrade down the road.
In the pilot program, the team determined the 10 most important BW queries and did the following "tests." They ran and measured query runtime without the BWA, ran the same load and measure query runtime with the BWA, and ran the same load and measure runtime without the BWA, but doubled the memory on a BW instance.
"The test results showed the BWA to be the winner hands-down," De Thomasis said. "In some cases, up to 65 times runtime improvements were measured once we activated the BWA."
The cost of the BWA is a major concern, but Australia Post will go forward with it because business requirements always come first, De Thomasis said. The organization is preparing for an influx of requests for analytical applications and complex, ad-hoc queries on employee mobile devices.
According to Werner Hopf, CEO of Dolphin, an SAP partner that specializes in information lifecycle management, the most important factors that go into the decision to implement BWA are the number of transactions loaded into cubes per time period, how frequently data from previous periods need to be modified, the number and complexity of queries, and the number of concurrent users running queries against the system.
Alternatives for improving BW performance
Customers need to compare the BWA expense with the labor effort (and data latency) of using aggregates in BW to improve performance, Schlegel said. And, like Australia Post, they need to compare the benefits and expense of buying BWA against throwing more hardware at the problem.
But there are other options for improving BW performance without purchasing a BWA.
For example, organizations should look first at tuning. There is a lot of tuning that can be done, Evelson said.
BWA is a necessary ingredient once you reach a certain size, Hopf said, but implementing ILM and archiving can dramatically improve query performance. A good strategy is to implement nearline storage first and then decide whether query performance justifies a BWA purchase. Organizations may find they can postpone a BWA purchase, or, when using nearline in conjunction with a BWA, at least reduce the sizing of BWA, he said. BWA and Dolphin's work can also be complementary solutions, where a customer using a BWA can lower the total cost of ownership and maintain performance by incorporating nearline storage.
Nearline, column-based storage gives organizations similar performance -- not quite as fast, but almost as fast, as BWA, Hopf said. It can reduce 20-minute queries to 10 to 20 seconds, he said. And it costs a lot less. Depending on the hardware architecture and vendor, hardware cost would be approximately $20,000 for a 5 TB BW system. Cost for a 1,000-user license is approximately $150,000. That's compared to around $675,000 for a 5 TB BWA system. Plus, ongoing storage and administration costs are reduced.
In turn, the nearline environment can be used for non-productive systems (QA, training, sandbox, etc.) without additional cost, Hopf said, while for BWA, at least a few blades would be required for a test system to perform integration testing.
"The core issue is really that the BW Accelerator is a point solution to address performance or query response time," he said. "But it's not necessarily the only ingredient to having an efficient overall analytics and business intelligence infrastructure in place."