Re: Data Warehouses

Joseph Wilson wrote:

> Does anyone have experience with large volume data warehouse? What kind of
> volumes have you seen that are feasible.

Volumes do not dicatate how usable or effective a data warehouse is. Design does. Both at a logical level and a physical level.

> The company I work for is looking
> to start a data warehouse project with data that will be coming off of the
> mainframe at about 1 million records a day at about 4k to 9k bytes per
> record(4 to 9 GB per day).

Peanuts. :-)

The rowsize is however much larger than the norm. However, if you do a proper star schema design, the physical rowsize of your fact rows will be much smaller as the dimension tables take care of that. I suggest not just dumping production data in production format with production designs and relationships into a database and calling it a warehouse.

> They want to store this in oracle for up to a
> year to be able to trend and aggregate the data. Has anyone seen a data
> warehouse implementation this size? Any tips or recommendations?

We have a smallish warehouse that I look after. Current row count of the largest fact table.. well above 700 million rows. Single physical table. But partitioned.

I suggest that you read the Data Warehousing manual that comes with the Oracle PDF/HTML docs. The important thing is to understand the concepts. The next important thing is to understand how to apply these technically in Oracle.

--
Billy