5/12/08

What Is Different Between ODS & IC


What Is Different Between ODS & IC

What is the differenct between IC & ODS? How to flat data load to IC & ODS?

By: Vaishnav

ODS is a datastore where you can store data at a very granular level. It has overwritting capability. The data is stored in two dimensional tables. Whereas cube is a based on multidimensional modeling which facilitates reporting on diff dimensions. The data is stored in an aggregated form unlike ODS and have no overwriting capability. Reporting and analysis can be done on multidimensions unlike on ODS.

ODS are used to consolidate data. Normally ODS contain very detailed data, technically there is the option to overwrite or add single records.InfoCubes are optimized for reporting. There are options to improve performance like aggregates and compression and it is not possible to replace single records, all records sent to InfoCube will be added up.

The most important difference between ODS and BW is the existence of key fields in the ODS. In the ODS you can have up to 16 info objects as key fields. Any other info objects will either be added or overwritten! So if you have flat files and want to be able to upload them multiple times you should not load them directly into the info cube, otherwise you need to delete the old request before uploading a new one. There is the disadvantage that if you delete rows in the flat file the rows are not deleted in the ODS.

I also use ODS-Objects to upload control data for update or transfer routines. You can simply do a select on the ODS-Table /BIC/A00 to get the data.

ODS is used as an intermediate storage area of operational data for the data ware house . ODS contains high granular data . ODS are based on flat tables , resulting in simple modeling of ODS. We can cleanse transform merge sort data to build staging tables that can later be used to populate INOFCUBE .

An infocube is a multidimentionsl dat acontainer used as a basis for analysis and reporting processing. The infocube is a fact table and their associated dimension tables in a star schema. It looks like a fact table appears in the middle of the graphic, along with several surrounding dimension tables. The central fact is usually very large, measured in gigabytes. it is the table from which you retrieve the interesting data. the size of the dimension tables amounts to only 1 to 5 percent of hte size of the fact table. common dimensions are unit & time etc. There are different type of infocubes in BW, such as basic infocubes, remote infocubes etc.

An ODS is a flat data container used for reporting and data cleansing/quality assurance purpose. They are not based on star schema and are used primaily for detail reporting rather than for dimensional analyais.

An infocube has a fact table, which contains his facts (key figures) and a relation to dimension tables. This means that an infocube exists of more than one table. These tables all relate to each other. This is also called the star scheme, because the dimension tables all relate to the fact table, which is the central point. A dimension is for example the customer dimension, which contains all data that is important for the customer.

An ODS is a flat structure. It is just one table that contains all data. Most of the time you use an ODS for line item data. Then you aggregate this data to an infocube.



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