Category: Open Source BI

olap4j version 1.0 released

Chris Webb2 Comments

Julian Hyde has just announced the release of version 1.0 of olap4j, the open Java API for OLAP, on his blog:
http://julianhyde.blogspot.com/2011/04/olap4j-version-10-released.html

I’ve been keeping an eye on this project not only because it allows Java developers to query Analysis Services via XMLA, but because I hope it will bring with it some good SSAS-compatible open source client tools. Out of the ones Julian mentions in his post, Saiku looks the most promising as far as I can see but when I have a spare moment I’d like to check them all out properly.

The only drawback with using olap4j with SSAS is that you need to configure http access to make it work, which is something most people don’t want to have to do. Hmm, wouldn’t it be nice if SSAS did this natively? Maybe it’s something that will come when we get SSAS in the cloud?

SQLStream and Mondrian

Chris Webb3 Comments

Interesting article here on Intelligent Enterprise from Seth Grimes on how SQLStream and Mondrian can be used together for real-time OLAP analysis on Twitter feeds:
http://www.intelligententerprise.com/blog/archives/2008/12/bi_on_content_f.html

More on the technical side of this from Julian Hyde’s blog earlier this year:
http://julianhyde.blogspot.com/2008/02/streaming-sql-meets-olap.html

I’m still not convinced there’s much of a market out there for real-time OLAP (as opposed to real-time BI); after all, how many people out there are actually using pro-active caching with Analysis Services? The kind of analysis you do with an OLAP tool, looking at high-level trends in aggregated data, seems to me to be the complete opposite of BI scenarios where you need to be able to respond instantly to certain events. But maybe I’ve just not come across the right business scenarios yet.

Pentaho 2.0 and Pentaho Aggregate Designer

Chris Webb2 Comments

Via Julian Hyde, I see Pentaho have released version 2.0 of their BI suite. As Julian points out in this blog entry here, one of the major new features in this release is the Pentaho Aggregate Designer, which makes it much easier to design aggregate tables for Mondrian. A quick look at the screenshot on Julian’s blog suggests that Mondrian is continuing to flatter Analysis Services by imitation (you can even see that the aggregations are being built on the Foodmart database!) – not that this is a bad thing, in fact it’s what makes Mondrian so easy to use if you’re used to Analysis Services.

So Mondrian is definitely catching up in terms of functionality… and in terms of performance, well, as Julian says "Mondrian is beholden to the RDBMS for performance" and those RDBMSes are getting ever faster. I suspect very soon more and more people are going to find that Mondrian plus an open source RDBMS (perhaps the column-store-based LucidDB, which I see already already has support for the new aggregate table designer) is going to be ‘good enough’ for many BI projects – after all, most AS implementations I see don’t involve massive amounts of data, and if Mondrian can give good query response times on a fact table of 20-50 million rows then the decision on which platform to use will be more heavily influenced by price. And what with the current financial crisis, price is going to be an ever-more important factor for many customers. I wonder how long it will be before I see MS BI consultancies starting to offer open source BI, given the relative ease with which you can transfer your cube design and MDX skills between the two platforms?

olap4j

Chris Webb1 Comment
I’ve just come across olap4j (http://www.olap4j.org/) which might be of interest for anyone out there working with Java to access OLAP cubes – as the website says, it’s like JDBC for OLAP (and so I guess you can also say it’s like ADOMD.Net for Java). It’s designed to work with a range of OLAP servers including AS2005. The interesting thing about it for me isn’t the cross-platform support, though, but that it in addition to support for MDX it will have an API for programmatically generating queries – something that I think would be useful to have in Microsoft’s own data access layer. Implemented correctly it would take away the need for programmers to have to learn about how to write efficient MDX and hopefully bring about a kind of standardisation of queries which would make writing calculations on the cube easier.

Cubulus – an open source OLAP engine

Chris WebbLeave a comment
I’ve had an email from Alexandru Toth about an open source OLAP project he’s working on. Here’s what he had to say:
 
I am developing an Open Source OLAP project  called "Cubulus". There is a presentation material at http://cubulus.sourceforge.net/   , and an online demo at  http://alxtoth.webfactional.com/  .The source code is at http://sourceforge.net/projects/cubulus/ .

In brief, Cubulus is an analytic engine + slice&dice web interface on top of relational database (MySQL at the moment) . It caches calculated cells, and is able to parse basic MDX queries. Project is in early alpha, and runs on  Mac OS X, on Windows .. and on Linux too 🙂

 
Perhaps not ready for the enterprise just yet, but still a worthy effort and any new OLAP that supports MDX is ok with me.

Playing away from home with Pentaho and Mondrian

Chris Webb2 Comments
Back in March, when I announced on this blog that I was going to set myself up as an independent consultant, I mentioned that I would be interested in doing some MDX work on other OLAP servers that support the language. Very soon afterwards I got an email from Nick Goodman at Pentaho asking me if I was interested in finding out a bit more about the open source OLAP server Mondrian and helping the open source BI community come to grips with MDX. How could I refuse?
 
Anyway, Nick pointed me in the direction of a very quick and easy to install demo of all of the Pentaho platform including Mondrian:
You literally download it (it’s about 100Mb), unzip it, click on ‘start-pentaho.bat’ and go to http://localhost:8080/pentaho/ and you’re there. Click on the ‘Steel Wheels’ sample and you can see demos of their reporting, olap and dashboarding tools. I’ve only really had a look at the olap stuff so far: in the Steel Wheels sample you click on ‘Pentaho Analysis’ and then ‘Territory Analysis by Year’ and you’ll see a pivot table (JPivot) and a graph; click on the MDX button at the top and you’ll see, and can alter, the MDX behind it. My first impression of this – and Pentaho Analysis is just rebranded Mondrian as far as I understand it – is just how conceptually similar it is to AS2K. Anyone coming from a Microsoft BI background will feel very at home with it. There’s a ton of documentation on Mondrian here:
…if you’d like to find out more.
 
Of course now I feel all guilty and adulterous (well, ok, not that bad) having strayed away from Analysis Services, but don’t worry – it will always remain my true love. But given that there’s such a shortage of people even in the Microsoft BI world that understand MDX I think there must be massive untapped demand out there for people who have cross-platform MDX skills: even though platforms like Essbase and SAP BW support MDX I’m sure you could count the number of Essbase and SAP BW consultants out there with anything more than a superficial knowledge of MDX on the fingers of one hand.