Question for integration star and snow flake schema in data warehouse

Dear Reader,
I facing a problem like that
I have two data warehouse, one use star schema, other use snow flake schema. I would like to integrate both of them into one data warehouse. What is the strategy should these two data warehouse adopt in order to integrate int one data warehouse?
Should I scrap both data warehouse and build a new one instead, or scrap one of them and use the other?
What factors should be considered in order for me to more easily resolve the differences between the two data warehouses.
Please advise. Thank you very much.

Hi Mallis,
This is a very broad question and the answer depends on so many factors. Please go through the following articles to get an
understanding of what the differences are when to use which.
When do you use a star schema and when to use a snowflake schema -
http://www.information-management.com/news/10000243-1.html
Star vs Snowflake Schemas – what’s your belief? –
http://www.networkworld.com/community/blog/star-vs-snowflake-schemas-%E2%80%93-what%E2%80%99s-your-belie
Hope this helps!

Similar Messages

Multiple star or snow flake schema for universe

Hi,
I would like to know following things
1. Can we use more than one star or snow flake schema for an universe? and how to do this?
2. Using multiple shemas for one universe is it good practice or not?
Regards,
Manjunath

Manjunath,
This is exactly where BusinessObjects excels.
When dealing with multiple fact tables, you use contexts.
Contexts are very simple to understand and you must take your time to do so if you are going to successfully develop universes based on more than one fact table. No matter what universe you build, the rule for contexts is always the same; there are no different circumstances based on, say, industry.
Each context starts with a base table, typically a fact table, where all its joins are at the many end of the relationship. The joins are then followed out through the joined tables up other joins where they in turn are at the many end, as in a snowflake schema.
For example, consider the very basic schema below:
D1 -< D2 -< F1 >- D3 -< F2 >- D4
There are two tables that only have many joins attached to them - F1 and F2.
Starting with F1, I can move to D2. I can also move from there to D1. In the other direction, I can move from F1 to D3. However, I cannot move from D3 to F2 because the join cardinalities are in the wrong direction. So, I've found all the joins that belong in the first context. They are D1-D2, D2-F1 and F1-D3. By the same process, I will get to the second context containing joins D3-F2 and F2-D4.
It doesn't work well with many-to-many joins, but you really shouldn't be facing these in a well-designed multi-star.
As for one-to-one joins, set the cardinality as one-to-many in the direction that you know the relationship should be in for the ownership to work out correctly..
The process that I've described above is essentially how the Detect Contexts algorithm works.
The only remaining thing for you to read up on is the SQL parameters but essentially you need ot be able to select multiple contexts and generate multiple sql statements for each context. Otherwise, what's the point in defining them?!!
Hope that clears it up for you.
Regards,
Mark

Star schema and snow flake schema

can any one tell star schema is better or snow flake schema is better why
thx in advance

Hi,
Difference : http://www.diffen.com/difference/Snowflake_Schema_vs_Star_Schema
When it comes to OBIEE star schema will be easy to configure because it don't involve much tables where as snow flake schema need to denormalize the tables in BMM layer to get the desired model but again it all depends on how your system was designed
HR schema which is more like a snow-flake schema structure
Refer http://www.varanasisaichand.com/2012/05/denormalizing-physical-tables-in-bmm.html
Thanks,
Saichand

Snow flake schema to star schema

Hi Gurus,
I am having a snow flake schema how can i turn it into star schema.
thanks,
kumar

In Obiee You can use multiple table source and join 2 tables abd make as singel table.
EX A->B->C
Now we need to join B,C and call it D. Then A->D is star Schema.
Steps is. Join B and C in the physical layer. join B to A Drop B into the Logical layer, Now Drop C on top od the B.
Table B wil get all the column from C. Here it wont create 2 sources, It will look like single source only.
IN the column mapping you can mpa the column to desired physical table.
Later as usula you can join B and A in logical layer.
Get A and B into presentaion layer.
mak if correct/helpful
fiaz

Reg Snow Flake schema design

Hi Experts,
Can any one post few scenarios regarding Implementation of snow flake schema which can not be converted to star schema in BMM layer for better under standing about schemas. I searched my blogs but i did not found exact answer.
Regards,
Rafi

Rafi,
Check these links
http://iniu.net/content/obiee-define-star-schema-over-snowflake-data-model-data-source
http://www.varanasisaichand.com/2012/05/denormalizing-physical-tables-in-bmm.html
http://majendi.blogspot.com/2009/01/obiee-snowflakes-and-stars-part-3.html
http://blogs.datadirect.com/2012/02/obiee-oracle-business-intelligence-integration-with-salesforce-com-crm-and-database-com-via-odbc.html
In general if you follow the OBI best practices you never get snowflake schema in BMM layer.
If helps pls mark

Snow Flake Schema

anybody give me some knowledge about snow flake schema.
in which type of situations,useually snow flake schema creates in data model.
can you please provide me with example?
Thanks in Advance.

In case of large dimesnsion, we will split them to smaller dimensions, this is to make the table better manageable.
Let's take an example you have a Dimension table which stores the information about the shop details, you may have a seperate dimension table which hold the dempgraphic information of the sales area this provide the logical separation of data.
You have to decide based on your data and requirement whether to go for snowflake or Star.
If you have snowflake defined, will be flattened the same in the logical layer of OBIEE.
Thanks,
Vino

Need a solution for integration BPM and UCM 11.1.1.4?

Hi all,
Currently, I am using BPM & SOA 11.1.1.4.
Could somebody advise me a solution for integration BPM and UCM ?
I heard somebody said that need to wait to BPM 11G patch set 5 (11.1.1.6) version, which have basic BPM and UCM integration and haven't to using external API like RIDC or CIS.
Thanks & Regards.
Ming Nguyen.

Do not use prebuilt binaries, but compile the package from source with the current libudev.
sha256sums=(SKIP)
source=("$pkgname::git+https://github.com/rogerwang/node-webkit.git#tag=nw-v$pkgver")
to build it in the PKGBUILD, use nw-gyp i guess.
Last edited by progandy (2013-06-21 22:54:36)

Pls send me PDF'S for Integration Repository and Mapping

Hello All,
I need to make presentation.
Pls send me different PDF'S for Integration Repository and Mapping
Regards

Henry,
I hope this will help you.
http://help.sap.com/bp_bpmv130/Documentation/Operation/MappingXI30.pdf
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/d046c490-0201-0010-84b6-9df523cbca31
raj.

HT5312 Hi, i'm forget answer for may security questions for Apple ID and can't reset it

HI. i'm forget answer for may security questions for Apple ID and can't reset it, after verified email adress the link for reset questions is not available.

The reset link will only show if you have a rescue email address on your account - if you've just added an address then it will be an alternate/secondary email address, which is a different setting/address on your account (a rescue email address can only be added by answering 2 of your questions).
You will need to contact iTunes Support / Apple to get the questions reset : http://support.apple.com/kb/HT5699
When they've been reset you can then use the steps half-way down the page that you posted from to add a rescue email address for potential future use

How to make snow flake schema to star in Business layer

i have snow flake data model.
anybody tell me how can i convert that snow flake to star by doing the adding multiple sources to a dimention.
how to do the joins with 2 dimention tables in the business layer

Hi
we can do that for example we have dimension table that connected with another dimension table in physical layer
solution- create one new dimension table in bmm layer and drag the columns from two dimension table which in physical layer and give the join condition it ll work,...
Regards
prabhu haridass

Why do we need SSIS and star schema of Data Warehouse?

If SSAS in MOLAP mode stores data, what is the application of SSIS and why do we need a Data Warehouse and the ETL process of SSIS?
I have a SQL Server OLTP database. I am using SSIS to transfer my SQL Server data from OLTP database to a Data Warehouse database that contains fact and dimension tables.
After that I want to create cubes using SSAS form Data Warehouse data.
I know that MOLAP stores data. Do I need any Data warehouse with Fact and Dimension tables?
Is not it better to avoid creating Data warehouse and create cubes directly from OLTP database?

Another thing to note is data stored in transactional system may not always be in end user consumable format for ex. we may use bit fields/flags to represent some details in OLTP as storage required ius minimum but presenting them as is would not make any
sense to user as they would not know what each bit value represents. In such cases we apply some transformations and convert data into useful information for users to understand. This is also in the warehouse so that information in warehouse can directly be
used for reporting. Also in many cases the report will merge data from multiple source systems so merging it on the fly in report would be tedious and would have hit on report server. In comparison bringing them onto common layer (warehouse) and prebuilding
aggregates would be benefitial for the report performance.
I think (not sure) we join tables in SSAS queries and calculate aggregations in it.
I think SSAS stores these values and joined tables and we do not need to evaluates those values again and this behavior is like a Data Warehouse.
Is not it?
So if I do not need historical data, Can I avoid creating Data Warehouse?
On the backend SSAS uses queries only to extract the data
B/w I was not explaining on SSAS. I was explaining on what happens inside datawarehouse which is a relational database by itself. SSAS is used to built cube (OLAP structures) on top of datawarehouse. star schema is easier for defining relationships
and buidling aggregations inside SSAS as its simple and requires minimal lookups to be performed. Also data would be held at lowest granularity level which can easily be aggregated to required levels inside OLAP cubes. Cube processing is very resource
intensive and using OLTP system would really have a huge impact on processing performance as its nnot denormalized and also doing tranformation etc on the fly adds up to complexity. Precreating a layer (data warehouse) having data in required format would
make cube processing easier and simpler as it has to just cross join tables and aggregate data based on relationships defined and level needed inside the cube.
Please Mark This As Answer if it helps to solve the issue Visakh ---------------------------- http://visakhm.blogspot.com/ https://www.facebook.com/VmBlogs

Questions for Integration

Hello,
Our VoIP Architect recently left the company as well as his knowledge and I'm just a data guy :-(. We are preparing to perform an integration for a new acquisition and out-sourcing was not considered prior to his leaving, plus funds may not be available to outsource. We will not be integrating there PBX into the infrastructure as we will be providing them IPT services.
My question to the forum is: what questions should we be asking to perform the integration with regards to VoIP.
1) What type of dial plan do they have
2) They will want to keep there DID so a port is needed with local PRI
3) I believe long distance will be provided through corporate
4) Do they have a night attendant
Any assistance is appreciated. Thanks
Anthony

Hello Anthony,
So you have the honor to learn VoIP on the fast track!? Well then let´s see the options.
First your questions are not bad, but only a small portion of the whole picture. The underlying question is: What functionality does telephony offer them now?The second question will be what are you able to reproduce with voip, what will be missing and what will be added.
About a few parts of functionality now:
- Availability (power, network, fallback scenario,...)
- Dial plan
- Voice mail
- 911
- call waiting/redirect/conference/...
- secretary function (rings ith boss phone)
- etc.
Now this is a lot of stuff to think about. So you can take everything at CCO that a search for "SRND voice" delivers you. SRND = Solution Reference Network Design, this is what you are asking for.
And doing this will show you that there is a lot more to tell than I could possibly write in a single post.
Another starting point would be "CISCO IP TELEPHONY SOLUTION" http://www.cisco.com/en/US/netsol/ns340/ns394/ns165/ns268/networking_solutions_package.html
Being a Global Knowledge Technical Instructor I would also like to point you to our Web page, where you can find the officil Cisco classes about IPT:
http://www.globalknowledge.com/training/category.asp?pageid=9&methodid=c&catid=206&country=United+States&translation=English
When you are interested in design then you could start with "IPTD (IP Telephony Design)"
http://www.globalknowledge.com/training/course.asp?pageid=9&courseid=9124&catid=206&methodid=c&country=United+States&translation=English
The other classes are more technology oriented and provide also hands-on to real euquipment.
Hope this helps! Please rate all helpful posts
Martin

Interveiw question for AD L3 and L4 level

Hi
I have asked below question in AD L4 interview question in one company?
What is disaster recovery in AD, any example?
What can be reason of user slow authentication in Domain for 1 site for multiple users and how can we check it from DC side.
Can i get more Question and answer for AD L3 and L4 level?

Hi
I have asked below question in AD L4 interview question in one company?
1.What is disaster recovery in AD, any example?
How to perform a disaster recovery restoration of Active Directory :http://support.microsoft.com/kb/263532
Active Directory Disaster Recovery:http://windows.uwaterloo.ca/server/disaster/ms_docs/disaster.htm
2.What can be reason of user slow authentication in Domain for 1 site for multiple users and how can we check it from DC side.
This could be due to dns misconfig,GPO causing the slow logon,health of dc is not good,Ad sites and service not set correctly etc.
Can i get more Question and answer for AD L3 and L4 level?
Hi,
See my line comments.Apart form interview question you need to create test lab and test the domain env.There are the infrastructure planning and design guides whci may be helpful to you.
http://www.microsoft.com/downloads/details.aspx?FamilyId=AD3921FB-8224-4681-9064-075FDF042B0C&displaylang=en
Hope this helps
Best Regards,
Sandesh Dubey.
MCSE|MCSA:Messaging|MCTS|MCITP:Enterprise Adminitrator |
My Blog
Disclaimer: This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.

Question for Markus Ganser and Klaus David

Markus and Klaus,
I recently joined a company Saqqara Systems, who is an SAP integration partner. We have a core focus around MDM enablement and Taxonomy Management. I was wondering if we might have a few direct discussions around how we can work together around some of your customers needs, we work with Kraft, Honeywell, Alcoa, Cooper, and a number of other significant SAP customers which are 100% referenceable. Put simply we offer an extremely streamlined and cost effective solution around managing Taxonomy, MDM data, and MDM quality. I would like the opportunity to share what we do directly with you and if you validate our solution would dramatically increase your Customer Satisfaction with their MDM initiatives get some recommendations on avenues which we could expand our partnership. I don't want to go into excruciating detail on the forum, however am confident I can prove our value. [email protected]

Hi Gary,
Many thanks for your post and your interest in MDM. I have forwarded it accordingly.
Kind regards, Markus

Sample questions for KMC-1 and KMC-2

Hi All,
I am preparing for SAP EP 7.0 Certification. Can someone provide mw with some sample questions of KMC-1 and KMC-2.
Points assured.
Regards
Nikhil

Hi Nikhil ,
Hi,
Look at this thread and you may also refer to these links
<b>https://forums.sdn.sap.com/thread.jspa?threadID=404007
https://www.sdn.sap.com/irj/sdn/thread?messageID=3418833#3418833</b>
Getting Started
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/webcontent/uuid/cacd8860-0a01-0010-a393-a7bdd1449487
eLearning sessions
https://www.sdn.sap.com/irj/sdn/km-elearning
KMC blogs
https://www.sdn.sap.com/irj/sdn/weblogs?blog=/weblogs/topic/17
KMC developer area.
https://www.sdn.sap.com/irj/sdn/km
http://help.sap.com/saphelp_nw04/helpdata/en/4c/9d953fc405330ee10000000a114084/frameset.htm
http://help.sap.com/saphelp_nw04/helpdata/en/1d/3d59fdaa5ebb45967ea107d3fa117a/frameset.htm
Thanx
Pankaj

Question for integration star and snow flake schema in data warehouse

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