Oracle BI EE Pro's:

1) Aggregate navigation

-- ability to set up aggregate tables in BI EE itself, which gives it 'aggregate awareness' while generating SQL. So if you have monthly sales aggregate you just set up BI metadata accordingly and all reports will target this table for monthly data.
There's no such feature in Cognos metadata setting.
But using this feature arises some questions:
a) whether aggregate definition should be BI-tool specific. A lot of practioners, including Kimball, insist that aggregate navigator should reside at database level so that every tool querying datawarehouse will benefit from aggregate avalaibility. This seems rather reasonable, since every datawarehouse is usually queried by more than one analytical application (BI, datamining, more BI) so you either direct all applications to BI EE, or agree to performance degradation.
b) aggregate tables desynch. When you just update the base fact table, aggregate tables become "out of synch", providing incorrect query results untill they're recalculated. This means that you either can guarantee that nobody will access reports in this period, or you can have incorrect data. Since more&more datawarehouses squezee load windows to reach real-time this problem gains priority.
c) choosing which agregate to use for answering questions. That's what statistics is all about in dbms, knowing number of rows and value distribution (lol). Oracle BI EE has the "table row count" feature (although I haven't seen it affect SQL generation yet, need more examples). But there's no value distribution analysis in there, so it's just one side of the coin (not talking about I\O device speed and other characteristics).

In general, it's recommended to use database-specific aggregate table functionality (Oracle Materialized Views or DB2 MQT) since it solves all the 3 questions given above and usually simplifies ETL process (and sometimes even speeds it up, since databases use their own transaction logs to detect what data has changed and what aggregates should be rebuilt). Too bad indexed views in Ms SQL do not work with aggregate dimensions (there's no way to define dimension hierachies there).

2) Cache management

-- OraBI has really profound cache management facility. You can "cache" any database query to OraBI specific storage structure (cache file), wich will allow subsequent queries to the same table\query to run without actual database request being made. This can greatly speed things up. I especially like the Event Polling Table feature: you add a table, which records when dwh table was last updated. OraBI then reads at given intervals and automatically invalidates old cache entries, based on this table records.
Moreover, if you have OraBI cluster this cache can be shared among servers.

There isn't anything even close in Cognos.

Although I greatly like this feature, I just want to warn about overusing it. It's easy to imagine BI developers boosting performance by adding more&more cache untill OraBI becomes a fully blown aggregate system. And sometimes it's just about 1 aggregate table at the dwh level ) Or about introducing OLAP server in the enviroment )))

3) SQL generation.

It's tricky subject, but for now I like OraBI generated SQL more. But it's "apples to oranges" for sure, since I usually use DMR's in Cognos which encumbers SQL greatly and there's nothing identical in OraBI EE.

Oracle BI EE Con's:

1) Multidimensionality

Cognos has Analysis studio and the ability to navigate hierarchies in both directions (you won't believe it, but in OraBI there's no 'Drill-Up', only'Drill-Down'). And DMR's and analytical functions (but their usage is a bit annoying, as it seems now, hope to write about it later). Anyway, Cognos is way much more 'multidimensionally-ready' than OraBI.

OraBI + Essbase is a work in progress and has a huge number of caveats (some fixed by patches, some not, some introduced). And the only way to use all Essbase functionality is to write direct MDX via Evaluate functions. That's a big problem, since it's hard for us to suggest OraBI on top of Essbase for now (till 11g once again). The only alternative is Visual Explorer, which is a very good tool, but it for top-analysts only (thick client, costly).

2) Metadata model development

Instead of OraBI's 'only-star schema', '3 layers of model' Cognos FM Manager doesn't impose any design principles, which allows more mistakes, but it makes some things way more simple. One of the first things I wanted to do in OraBI was a report using just a single table.  Well that's a really funny exercise (see posts over here) if a star schema is a must.

But the main problem is the lack of API for metadata changing and browsing. There's udml, but it's not supported officially. Therefore all current integration scripts (like adding users, merging repositories and working with hierarchy depth changes) are out of the law. Which doesn't stop anyone, but is pretty annoying.

3) Pixel-perfect reports

Oracle BI Publisher is a specific tool, aimed at generating a huge number of formatted reports, based on XML format definition files. It wasn't a part of Siebel BI, so 'integration stitches' still stand out. It's a nice tool, but it certainly lacks web-interface ) Therefore in Oracle BI there's a deep distinction between a simple formatted report (with lots of possible logic in it) and making this report 'printer-friendly' since for the latter you basically have to start from scratch by opening Ms Word )  This will change in 11g as they say )

Having said all that, I really wait for Oracle BI 11g edition to start using it with Essbase and I kinda like the product as it is for "relational-only" reporting.

I surely wanted to write a simple bullet point list at first )

Those who aren't struck by occasional CAM-AAA-0071 “An internal error occurred” which stops the whole server can skip this post.
This error was discussed at:

http://www.ibm.com/developerworks/forums/thread.jspa?threadID=244357

http://www.cognoise.com/community/index.php?topic=4971.0

The story goes like this:
- java.exe (that powers BI), grows up to the point where it cannot obtain contigious memory from server and crashes
- Cognos BI doesn't recognize this error, so it throws out a general CAM-AAA-0071
- Cognos BI is unaccessible until restart

This error occurs more often in heavy-usage enviroments. In one of our projects, with lots of Event triggered admin-links and reports, it took only a coulple of hours before it striked.

Solution is not complete, but as I see it now:
1) Put the latest SP on BI (or a special hotfix, if one is avalaible)
2) Lower the avalaible memory for Cognos BI service (to 768 mbs)
3) Modify the HeapDecommitFreeBlockThreshold registry property

It's interesting if 8.4 is prone to such error.

PS: I'm a certified Cognos Technical Specialist now, as well. Need to get first-line support partnership, you know )

With mostly very cryptical error messages or without any.
One of the problems might be just that DataManager service (which does the transfer) cannot allocate enough memory for operation. This is what we've encountered just today.

Good news are that this parameter is easily configurable, you can just edit cognos_install_path\bin\dataimportserviceconfig.xml file and set JMX (Java maximum allocated memory) to something more appropriate than default 128M (1024 is a nice number, for example).

Try this if your links fail

PS: In this 'wonderfull' Java world, setting JVMX is a common boost-up technique. And there's a lot of places to apply it. Think about Cognos Rich Client Platform (Cognos 8.4 Contributor) for start...

Reasons vary, but mostly it's that I've been, you know, busy-busy. As I now start to reflect on it, it's always a point of view thing and a question of self-control and ability to say no )

But enough philosphy, brief recap on what happend while I was out "there" in real world. I'll divide this into two parts (by vendors ))

Big Blue

Made some POCs in autumn, nothing that special (some neat integration, but not cognos-related). Carried on a couple of projects with  EP+BI typicalities. All in all, nothing that new.

BUT I've finally completed the other certification path there is at Cognos\IBM, notably, the "BI Professional" road. It's a deal longer, as of now, you have to pass 3 "role-based" exams, 2 mandatory (Report Author and Metadata Model Developer) and one of you choice to get a chance of passing BI Pro exam. It's used to coast 10k, which could be cut down to reasonable 200$ if you attended a Cognos Workshop (which costed 2,5k), but thanks to IBM that's gone and now it's 200$ from the start. Just opened certifications link and I'm, frankly, quite surprised with new IBM names for old Cognos certifications. According to this I'm:

• IBM Certified Designer -- Cognos 8 BI Reports
• IBM Certified Developer -- Cognos 8 BI Metadata Models
• IBM Certified Developer -- Cognos 8 BI OLAP Models
• IBM Certified Solution Expert -- Cognos 8 BI

and it turns out I was an

• IBM Certified Solution Expert -- Cognos 8 Enterprise Planning

instead of Cognos EP Professional.

Wording is something you cannot easily take from IBM ) Will put that list in about page, just to get more mail asking for exam questions.

Hint: In comparison with the old Modeler exam, current one is easier.

And in the first 2 months of this year we did a "nightmare-style" POC with EP + TM1 + BI, where I could finally get an idea of what TM1 really is and fully realize some ideas like incremental administration links and, therefore, "real-time" EP -> TM1  data propagation. I'm planning to write about this in separate posts, though. And, boy, it was hard, and we flanked the final presentation due to me being ill and bla-bla, and I'm still recovering breath from this.

But enough about IBM, let's turn to

Oracle

We've made a really nice billion-facts cube with our colleagues from "SportMaster" and talked about it in exceeding detail on Russian Oracle Technical Forum 2008 and Oracle BI Forum 2009. Essbase turned out to be a good engine for this kind of task and the moment when it finally kicked-in on 100gb dataset will retain as one of best in 2008. The fact that one of dimensions was a million rows parent-child didn't raise that much of a problem.

Moreover on another site we duly built dimension outline with around 30 mln members. Although duly is not the right word, "kicking and screaming" would be a better wording ) And the whole area of trying to tune something in underlying Berkeley DB is still open. But I must admit, an 8 gb outline file is really impressive.

So I've spent pretty much time toying around with essbase (except when I wasn't with TM1)). And I'm also a Hyperion Essbase 9.3 Developer Certified Expert (I won't enter Prometric for a while, I hope).

So it was a rather crowded time and I hope that nothing will stop me from blogging some details and future encounters. At least, I'd try my best to. Cheers to your patience, folks )

In deep 90s a great guy named George Kunzle lead the development of IBM internal budgeting system, called FREGI. It was written in APL and had very good UI, they say.

After some time, Kuntze quit IBM and left for good in the big open world, where he met Guy Haddleton, former SAS captain, at the time a CEO of 2-people company (with Kiwi Sue Strother)  called Adaytum, based in Haddleton's appartament in Bristol. Adaytum was selling rather cheap spreadsheet budgeting solutions. After some rewrite FREGI became Adaytum Analyst, leading product in the rapid-growing market.
Later, Analyst was rewritten on dyalog apl, giving it a windows gui.

Soon they had to find out how to scale this system to enterprise level. And there appeared Contributor, giving every user a cut-version of analyst written in J (cause it's free of charge, maybe) and  wrapped in ActiveX to sit in a browser nicely.
And then Adaytum was snapped by Cognos (it was Adaytum 3.0, and Contributor appeared in Adaytum 2.4 (i've started with that one)). A tough road of integration BI products with Adaytum was taken and now they are almost inseparable (at least we do not implement "ep only" anymore).

And now Big Blue snapped little Canadian and a loop tied.

I wonder, did anyone welcomed FREGI back?