Created by Tamas Simon. Sponsored by PerformanceG2, Inc.
I just wanted to leave an encouraging comment - I think it's FABULOUS that you are doing this site. I don't think I've seen one like it anywhere else. I hope you keep doing it. I've been looking for information on DMR for awhile now, and your site is the only place that even comes close to covering it. I'm wondering how to alert more Cognos developers about the site.PRASANNA said...
This information regarding Cognos DMR technique was really useful and thanks Simon for this great work.Jonty said...
Its great to know that someone is putting real experience stuff and excellent technique.Art said...
I am surprised, amazed, and grateful for people like you who are so generous with their knowledge. Again, THANK YOU!
I'm a novice about MDX, but I understood, after many hours, that my calculated measure was to be a mix between value and tuple, but it's been difficult to find the right page on the net. Your blog on that is the best one. Clear and simple.
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It is a trim down version with TM1 engine.
ReplyDelete"in-memory OLAP engine" sounds scary... it may work for small businesses...
ReplyDeleteWhere I come from the whole point of OLAP is that it's pre-calculated and persisted.
Ok, this is long but it'll help whoever's considering Cognos Express. We bought Cognos Express when it first came out last year, in the end we upgraded to Cognos 8 in August. I was hired after Express (Reporter) was purchased but was then assigned to evaluate everything else about Express for our uses. Here's my review of Cognos Express:
ReplyDeleteCognos Express is a severely handicapped version of Cognos 8.4.1.
The product correlations are as follows:
Express Reporter = Report Studio (express & pro modes) with Framework Manager.
Express Advisor = Analysis Studio, again with FM.
Express Xcelerator = TM1
There are two large problems I must point out. First, the documentation for Cognos Express is wrong in many cases. It seems IBM was in a rush to release this product and directly copied the Cognos 8 documentation for those products - but express is handicapped and the documentation wasn't modified to adjust for that (at least as of two months ago). The other main problem is that Cognos support reps don't seem to be sufficiently trained on the differences between Express & 8. They're learning the differences by trial and error. We were lucky enough to get an express developer on one of our problems (that regular support couldn't solver after a few weeks), that helped significantly.
Aside from how these modules (purchased separately) are only pieces of Cognos 8, the primary way they are handicapped is in terms of supported data sources. Note that for each of the items below, lack of a true native connection mainly means you lose the vendor specific functions (functions for the system your connecting to being ported over the program you're using), this makes development more difficult in some cases. Particularly data modeling.
Express Reporter: The documentation says it supports everything Report Studio & FM do but that's wrong. It does access most RDBMS through ODBC, but true native connections are pretty sparse. Reporter can only access OLAP cubes from Xcelerator Server (TM1). Express Reporter 9 is built directly from report studio 8.4, it's basically code ported over. The interface is the same, base code is the same, etc. This was a life saver enabling us to upgrade to cognos 8.4.1. The reports & data modeling we created in Reporter & FM were very easy to migrate to our new C8 server, I just exported/archived everything to a zip that C8 let me import. I expect that migrating from Cog Express to Cognos 10 (not released yet) would have some issues. The only issue I had when migrating from Express to C8 is with the security configurations. Express has different user types/names/capabilities and this broke things when everything was imported into C8. I had to delte the Express user types and manually reset the capabilities/permissions for much of the C8 user types.
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ReplyDeleteExpress Xcelerator: This is the "In memory OLAP engine" referred to in Cognos Express. According to the IBM support escalation team, Xcelerator server is identical to TM1 and they didn't change anything but the name. This is not 100% true. While evaluating Xcelerator (& working with that escalation team) we found that the 64bit installation option of TM1 is not available in Express. I can't remember if LDAP is supported, just that I had issues trying to make that work. Like TM1, Xcelerator does have the excel plugin for pulling data form TM1 cubes and doing analysis. If setup correctly, the excel docs can write data back to the TM1 cube (this seems more painful than you'd expect since you need to model it to handle writebacks). TM1's TurboIntegrator does have a native connection to MSSQL 08, but not MSAS. Supposedly MSAS works as a source and TurboIntegrator can even pull/replicate cubes (not link - dumb, i know) but it always failed. Support couldn't figure it out and more than a month later just said it's not supported. You cannot use TM1 to simply link your MSAS cubes to make them available to Reporter, reporter has to actually pull things from TM1 cubes or relational sources modeled with FM. This is a pain, especially since the TM1 interface seems subpar and we've already developed cubes in MSAS. TM1 also is not as scalable, there are performace issues. TM1 isn't built for multi-threading/parallel processing, the best it can do is give a thread to each report user. I think it's creating another instance of the process that user is calling to retrieve data.
Express Advisor: I never installed this module and can't give a full review of it. It appears to be analysis studio, FM, and some other little piece for forecasting. I expect it would have the same type of data source limitations as the others.
Benefits to Cognos Express: If it exactly fits your needs and you don't have the resources to buy the regular cognos or some other solution (note they do have some different pricing for smaller companies) then I guess that's your best option. I see how it could work for some small businesses, it just didn't work for ours. We only have about 100 employees but we deal with a very substantial amount of data. Basically, if you have and expect to have small amounts of data, don't already have your infrastructure in place, can mold your systems to the cognos express model (relational DB into TM1 cubes) and go from there, then you should be alright. If that's not you, buy something else. You'll greatly appreciate the full features, documentation, & support you'll find with other products.
Cheers
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ReplyDeleteExpress Xcelerator: This is the "In memory OLAP engine" referred to in Cognos Express. According to the IBM support escalation team, Xcelerator server is identical to TM1 and they didn't change anything but the name. This is not 100% true. While evaluating Xcelerator (& working with that escalation team) we found that the 64bit installation option of TM1 is not available in Express. I can't remember if LDAP is supported, just that I had issues trying to make that work. Like TM1, Xcelerator does have the excel plugin for pulling data form TM1 cubes and doing analysis. If setup correctly, the excel docs can write data back to the TM1 cube (this seems more painful than you'd expect since you need to model it to handle writebacks). TM1's TurboIntegrator does have a native connection to MSSQL 08, but not MSAS. Supposedly MSAS works as a source and TurboIntegrator can even pull/replicate cubes (not link - dumb, i know) but it always failed. Support couldn't figure it out and more than a month later just said it's not supported. You cannot use TM1 to simply link your MSAS cubes to make them available to Reporter, reporter has to actually pull things from TM1 cubes or relational sources modeled with FM. This is a pain, especially since the TM1 interface seems subpar and we've already developed cubes in MSAS. TM1 also is not as scalable, there are performace issues. TM1 isn't built for multi-threading/parallel processing, the best it can do is give a thread to each report user. I think it's creating another instance of the process that user is calling to retrieve data.
Express Advisor: I never installed this module and can't give a full review of it. It appears to be analysis studio, FM, and some other little piece for forecasting. I expect it would have the same type of data source limitations as the others.
Benefits to Cognos Express: If it exactly fits your needs and you don't have the resources to buy the regular cognos or some other solution (note they do have some different pricing for smaller companies) then I guess that's your best option. I see how it could work for some small businesses, it just didn't work for ours. We only have about 100 employees but we deal with a very substantial amount of data. Basically, if you have and expect to have small amounts of data, don't already have your infrastructure in place, can mold your systems to the cognos express model (relational DB into TM1 cubes) and go from there, then you should be alright. If that's not you, buy something else. You'll greatly appreciate the full features, documentation, & support you'll find with other products.
Cheers
One other note on the "in-memory OLAP engine" I forgot to mention before. There is another aspect of this, if you're making reports based off anything but power cubes cognos (both express 9 & BI 8.4) will pull the data & create an in memory cube to run the report against. This can be problematic. The only way out of this is to report off of power cubes.
ReplyDelete