Cognos BI

Oracle BI

• performance is allways a consideration, full-table scans are unpredictable
• there's always 'local processing' vs 'database only and some things not working' dilemma
• using multidimensional functions in reports is oh-so-hard to debug when they don't work in complex situations.

I'm really frustrated by this.

Using Active Directory in Cognos and Oracle BI

Cognos

Oracle

Extracting Active Directory information to csv

Links for extracting Active Directory information to csv:

Step by Step Active Directory Export Guide
http://www.rlmueller.net/ADOSearchTips.htm
http://www.computerperformance.co.uk/Logon/LDAP_attributes_active_directory.htm
JXplorer -- a graphical tool to browse any LDAP server

ODI repository creation is sucessfull, but after that Topology Manager and all other ODI modules won't work, throwing "ORA-12705: invalid or unknown NLS parameter value specified" while connecting to XE.

There are 3 java connections to repository in ODI:
1) For Oracle Data Integrator Modules

Unfotunately, I couldn't get ODI to work with correct NLS by changing odiparams.bat as they recommend on Metalink, but downloading latest jdbc driver from Oracle and removing old ones (physically deleting ) from \drivers folder helped with this part.

2) For ODI Agent

After trying in vain with adding "-Duser.language=en" "-Duser.region=US" to odiparams, I've created a new wrapper configuration file (stored in ODI_HOME\tools\wrapper\conf) by copying snpsagent.conf to and adding this options to line

wrapper.java.additional.1=-Djava.security.policy=server.policy

so it read

wrapper.java.additional.1=-Djava.security.policy=server.policy -Duser.language=en -Duser.region=US

reinstalling agent with the new wrapper conf file (you explicitly run 'agentservice -i -s agent_name 20910 new_wrapper') worked.

3) For Metadata Navigator

I've used Apache Tomcat as a Metadata Navigator container. Setting additional java options (the very same '-Duser.language=en -Duser.region=US') for tomcat solved this one.

See related Metalink Note: 471749.1

BI

CPM

The CPM Big Three(aka leaders quadrant) is formed and I think they'll just waltz around the quadrant in next couple of years.

PS: Just to notice, they say aggregate awareness for Cognos BI is in beta-testing. Just after I spent so much space promoting database-level aggregate navigation.

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 )

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 )

And, more important, this book really gives you an overall picture and shows a way to go. DBAG covers every topic with excessive amount of details so you can't see the forest over the trees.

Kudos to Edward and Tracy, it's a fantastic job. I'm waiting for ASO one.

PS: Too bad it wasn't there a year ago. And too bad there are no such books on cognos
PPS: Edward has a blog, as you all know.

PS: I have very special attitude to David Lynch's films. A physical one. Just the sight of road running away at "Lost Highway" makes me creepy. It takes me about 5 seconds to identify Lynch's work, as I've found out while watching "Chacun son cinema". Might be camera angle...