Final answer:
Graph decomposition is the process used to convert an entity-relationship graph into a set of relational dataframes or tables, involving creating tables for entities and relationships and applying normalization to ensure the database structure is optimized.
Step-by-step explanation:
To turn an entity-relationship (ER) graph into a set of relational dataframes or tables, one would typically engage in a process known as graph decomposition. This involves identifying each entity and relationship in the ER diagram and systematically creating relational tables that represent these concepts. The attributes of the entities become the columns of the tables, while relationships may necessitate the creation of additional tables or the use of foreign keys to maintain referential integrity between entities.
The process involves the following steps:
- Identify all entities in the ER graph and create a separate table for each entity with its attributes as columns.
- Identify relationships between entities and determine how to represent these in the database - one-to-one, one-to-many, or many-to-many - which may require creating additional tables or establishing foreign keys.
- Enforce referential integrity by using foreign keys that reference primary keys in other tables.
- Apply normalization rules to ensure that each table is properly structured to reduce redundancy and dependency.
This methodical approach is crucial in transforming an ER diagram into a well-structured relational database. Normalization is also a part of the process but in the context of refining the database design rather than the initial conversion from graph to tables.