The difference between a relational database and a multi-dimensional database

Question:

Preliminary understanding of multidimensional database and relational database are table storage, but in the cube is called the fact table, the dimension table, do the analysis of the relational database can do it? (the book says that the multidimensional database queries faster, but why is it faster?) are multidimensional databases and relational databases simply better at query speed? And what are the considerations for building a multidimensional database?

Answer:

My understanding is as follows:
Relational data Warehouse design in strict accordance with the three-paradigm design, in the data query, the need for multiple table connections to achieve, for large data volume of the warehouse, such a connection is very time-consuming, so poor performance; This structure also leads to a long development cycle, high cost, but space-saving, easy to expand, is the ideal warehouse design method.
At present, the use of multi-only design method, this method with the fact table as the core, a number of dimensions combined, simple and easy to understand the structure, development is relatively easy, this structure led to a lot of redundancy, but because of this, but also improve its performance, that is, the so-called space-time;

The difference between a relational database and a multi-dimensional database