Fundamental terminology: Please explain

[datanibbler]

Hi,

I am pretty much through reading my ebook "QlikView 11 for Developers" and well into my work, but I think I've skipped a fundamental piece of knowledge:

Can anyone please explain to me the terminology used in the book of "fact tables" and "dimension tables"?

From my former work,  I am used to the terms "transaction table" (e.g. the BSEG table in SAP, where data is stored on a very detailed level - every individual transaction is there) vs. "masterdata tables" (where non-redundant masterdata is stored (e.g. vendors' names) which is used in several other tables.

I guess understanding that difference is crucial, e.g. to aggregating data.

Thanks a lot!

Best regards,

DataNibbler

[hic]

"Fact table" and "Transaction table" are almost the same. The difference comes from what type of system you are working with : Transaction tables are found in OLTP systems, where you can have several transaction tables on different levels, e.g. order header (BKPF) and order lines (BSEG). "Fact table" is the term used in business intelligence, where often all numbers must be stored in the central table of a star scheme - the Fact table.

The difference between "Dimension" and "Master table" is the same as above. "Dimension" is the BI term and "Master table" is the OLTP term.

So, basically you don't need to bother about these differences.

HIC

[datanibbler]

Hi Henric,

thanks a lot! I thought they must be approx. the same, but knowing for sure that it is so does help. Knowing the difference between the two is crucial when aggregating data on script level - which in some cases will be preferable to aggregating in a chart for the obvious reason of RAM usage.

Thanks a lot!

Best regards,

DataNibbler