Re: Star Transformation

Dino,

Bitmap index may not help depending on volumn and cofiguration. If you want to test and try star schema, try DIMENSION and MATERIALIZED_VIEW. Hope this can help you.

Reid

Dino Hsu wrote:

> Dear all,
>
> I've just read Chapter 16 Schmeas, Oracle8i Data warehousing Guide
> Release 2 (8.1.6), I found star transformation to be very interesting.
> I want to confirm my understanding about how star transformation
> works:
> 1.The initialization parameter STAR_TRANSFORMATION_ENABLED set to
> true.
> 2.Bitmap indexes created for all foreign keys of the fact table.
> 3.Bitmap indexes created for primary keys of the fact table and for
> large dimension tables. (full table scan is fine for small dimension
> tables)
> 4.Remote small dimension tables are allowed, but not the fact
> table.(not sure)
> 5.Star transformation is general enough to include both star schema
> and snowflake schema. In my idea, star schema is a special case of the
> more general snowflake schema.
>
> Thanks,
> Dino
Received on Wed Oct 10 2001 - 06:29:29 CDT