勤快的小猪

Considerations on Oracle RDW vs RDM written by Alvaro Silva under ORDW, Oracle Retail

ORDW is the Retail oriented Data Warehouse that Oracle provides, part of the Oracle Retail suite of products, to support retailers in their decisions. ORDW is in version 13 and I have worked with this product since version 9.3 (Retek old times). This product is alive and going pretty well so far with the OBIEE now as the BI platform to support ad-hoc reporting, instead of the previous Microstategy.

The picture below depicts the current approach of the RDW:

A few weeks ago I have started to install the ORDM for a small POC. Since it is mainly based in Inmon’s paradigm, and I haven’t implemented so far, in my career, a Retail DW using this approach, it was a good opportunity to go on with some experiments, during my dead times inside some hotel, with this promising product. My main objective was to evaluate the product.

Theoretically Inmon’s philosophy around the initial design of an Enterprise 3FN data warehouse and then data marts sourced by it, are perfectly represented with ORDM. To be honest, looking at the product, at first sight, it looks a lot more blurry than RDW looked to me some years ago. This is natural since Inmon’s paradigm is professionally new to me, I am not a real follower of his paradigm, and because Kimball was greatly emphasized during my university times, and inside the literature I am really used to read.

So, in a few words, ORDM is just another approach for building a data warehouse, not from scratch, offering a retail base product based on the ARTS standard.

Technologies involved with ORDM

There are several technologies around base installation of ORDM, based on the Oracle large set of new products. The Oracle Database should be 10g latest version or the 11g (11.1.0.7 preferably), have the OLAP and Mining options included (if installed) with analytical workspaces and models pre created. Several patches are required to put things working properly, like described inside the installation guide. Any developer can use AWM/OX/OWB to manage the AW’s, and OWB to manage the Intra-ETL packages that are also part of ORDM.

Unfortunately/fortunately the RDM is not a specific product to Oracle Retail sources. ORDM is a real generic base data warehouse, based in the ARTS 5.0 standard, which can indeed be used to support Oracle Retail sources, or any other retail source like SAP Retail.

During the installation of the product it provides some samples, not supported by Oracle, which can be indeed a very good help during the developments of new user defined dashboards/reports. I had a few problems installing the OLAP part of the samples, mainly because AW’s have still some issues with distinct version of the option and the AWM itself. Both must be coherent with the indications that the guide describes.

External interfaces into the ORDM do no exist! Some years ago I have used ODI (old Sunopsys) to create a few interfaces into a few data marts. Using ODI was simple, accessible, and with just a few steps, a few knowledge modules, topology well defined, and voila the interface was done. Now I still don’t know which technology is the best, since Oracle has already a few of them, and each post I read refers something different. Informatica is another option or even OWB can also be used here. Or even RETL with OWB. Whatever technology is used for “Extra-ETL”, it doesn’t really matter, I am sure that things will work perfectly. For now, looking at some feedback provided by some Oracle colleagues, ODI is to way to go. Let’s see.

The use of the OLAP Option was not new to me. But I really still have some concerns about using it. Since 9i version I have researched this option with plenty of examples using JDeveloper with BI Beans and a few cubes. During that time I found out that the idea of having everything in the database was great, but, to be honest, the results I had (performance and space) disappointed me a lot. The Option had lots and lots of bugs, it didn’t have a minimal suitable performance compared to other tools like Microsoft Analysis Services. With those results, I really quit considering it for an internal project. With version 11g, and future versions, we expect much more! Personally I believe in this product! Therefore I will do the same exercise of analysing the behaviour of this 11g Option with my old tests in 9i.

Regarding the Mining Option, I have applied a few Data Mining techniques already using the product for my master’s academic project. In the previous version I have tested it for a Classification problem using decision trees (I believe it has a variation of the CART algorithm). It worked perfectly, but the output I was expecting was not sufficient compared to any other academic tool. Nevertheless, I believe that with 11g, again, things get better and the ODMiner GUI and the Mining Option have been improved. For me, at least, during my short readings, I know now that the tree design model output already exists, which makes me a little bit happier.

I am researching ORDM deeply now, looking at the current functional model which interests me most, in a business perspective, and learning in parallel the latest Oracle technologies involved. Great! For now The Oracle ORDM forum is almost empty, a few colleagues are helping me with a few suggestions; Metalink doesn’t have a lot of information regarding the product, which makes me wonder why? I will continue with this investigation, since I have already planned to provide the POC on this in a few days.

ORDM Provided Samples

The provided samples are somehow easy to install. Nevertheless some DB, OBIEE, option OLAP, option Mining knowledge is required to put things working properly. The OLAP option requires a few extra DB optimizations to have a minimal performance.

Analytical Workspace:

Opening the AW Manager I can already see the four provided  cubes: OOS_INV, OOS_INV_FCST, OOS_SALES, OOS_SALES_FCST. Nevertheless I am still getting really poor performance in maitaining the cubes using a virtual machine for testings (2MB RAM).

OBIEE Metadata

Opening the OBIEE Administrator with the provided repository returns already metadata to the ORDM model, including the Mining tables and the OLAP views. For now everything is pretty straight if you understand all the technologies involved. During the installation of this sample, make sure your connection pool is well configured inside the administrator GUI (windows side).

Business Areas sampled without OLAP and advanced analytics

Used Data Mining Models

Final Considerations

For me, both products are suitable! When shall we implement Kimball or Inmon paradigm? If I don’t use Oracle Retail sources should I use the ORDM model based in Inmon?

Why ORDW? Why ORDM?

For me there are several great benefits of still having RDW implemented:

1. It uses a clean, easier, Kimball’s like approach for the data model design, which makes it easy to understand and extend it, in the future, to support other missing retail areas. Since RDW is not perfect, it doesn’t have, vanilla, data marts for some of the operational areas that exist inside the operational applications of the Oracle Retail suite. Using this design paradigm, it is somehow easy to design a new sub model and an ETL interface to accomplish it.

2. The ETL framework that RDW uses, for many users, it was a big “black box”. For me, on the other side, during my old professional years has a technical analyst, I found out that even not being the best solution to have RETL interfacing to this DW, it works perfectly when the data volume is not that high, and it’s portable because of JAVA. Besides, the RETL framework improved a little bit since 9.3: e.g the debugging option was improved, making it easier to maintain/analyze the interfaces. In a developer perspective, the base libraries, provided in the form of korn shells, if well used, can simplify very much their developments, becoming pretty straight and simple to develop new data flows with this framework.

3. RDW connects directly to the operational systems like RMS (Oracle Retail Merchandise System), using flat files attached to a fixed schema with pre-built interfaces, which makes it easy to implement it against other OR modules. Plug and play the “in-box” interfaces and you have already a vanilla implementation of this product up and running.

So, for now, I cannot say for sure if ORDM substitutes ORDW. Sincerely I believe it doesn’t because they are different products.

Nevertheless, it’s another option for a base Retail data warehouse implementation, with Inmon’s paradigm for data warehousing. The “winner” will be the simpler/cheaper (nice dilemma) to implement, since it will be hard to convince many users to pay for the effort of building interfaces for scratch for a simple similar RDW implementation in ORDM, and the use of multiple paid technologies. Besides, Inmon’s approach is always harder to understand, more complex, compared to Kimball’s, and theoretically with less performance.

During the next posts I will try to write my opinion about this approach.

posted on 2009-11-18 11:21 噜噜 阅读(4988) 评论(0)  编辑  收藏


只有注册用户登录后才能发表评论。


网站导航:
 
<2009年11月>
25262728293031
1234567
891011121314
15161718192021
22232425262728
293012345

导航

统计

常用链接

留言簿(2)

随笔档案

Oracle Data Mining | + KDD

Oracle OLAP

搜索

最新评论

阅读排行榜

评论排行榜