What are the strength of Dimensional Modeling?

Data MiningDatabaseData Structure

The dimensional model has several important data warehouse advantages that the entity-relationship model lacks. First, the dimensional model is certain, standard architecture. Document writers, query devices, and user interfaces can develop strong assumptions about the dimensional model to create the user interfaces more understandable and to make processing more effective.

For instance, because some constraints set up by the end-user appear from the dimension tables, and end-user tool can provide high-implementation “browsing” across the attributes inside a dimension via the need for bit-vector indexes.

Metadata can need the known cardinality of values in a dimension to model the user terminal behavior. The predictable structure provides immense benefit in processing. Instead of using a cost-based optimizer, a database engine can develop powerful assumptions about first constraining the dimension tables, and thus “attacking” the fact table all at once with the Cartesian product of those dimension table keys fulfilling the customer constraints.

A second strength of the dimensional model is that the predictable structure of the star join schema hold off unexpected changes in client behavior. Every dimension is equivalent. All dimensions can be thought of as symmetrically equal entry points into the fact table.

The logical design can be done virtually independently of normal query patterns. The user interfaces are symmetrical, the query strategies are symmetrical, and the SQL generated against the dimensional model is symmetrical.

A third strength of the dimensional model is that it is easily extensible to contain unexpected new data components and new design decisions. First, all existing tables can be changed in place either by simply adding new data rows in the table or by executing an SQL ALTER TABLE command.

Data should not have to be reloaded. Graceful extensibility also defines that no query tool or documenting tool is required to be reprogrammed to hold the change.

A fourth strength of the dimensional model is that there are several standard approaches for handling common modeling situations in the business world. Each of these situations has a well-understood group of alternatives that can be expressly programmed in document writers, query tools, and multiple user interfaces.

A final strength of the dimensional model is the increasing body of administrative service and software processes that handle and need aggregates. The aggregates are summary records that are logically redundant with base data that is already in the data warehouse but are used to greatly enhance query performance. A comprehensive aggregate method is needed in each channel and huge-sized data warehouse execution.

raja
Updated on 09-Feb-2022 13:08:29

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