Getting Started with Data Modeling

A data model is a representation of the information consumed and produced by a system, which lets you analyze the data objects present in the system and the relationships between them. PowerDesigner provides conceptual, logical, and physical data models to allow you to analyze and model your system at all levels of abstraction.

• Conceptual Data Models
  A conceptual data model (CDM) helps you analyze the conceptual structure of an information system, to identify the principal entities to be represented, their attributes, and the relationships between them. A CDM is more abstract than a logical (LDM) or physical (PDM) data model.
• Logical Data Models
  A logical data model (LDM) helps you analyze the structure of an information system, independent of any specific physical database implementation. An LDM has migrated entity identifiers and is less abstract than a conceptual data model (CDM), but does not allow you to model views, indexes and other elements that are available in the more concrete physical data model (PDM).
• Physical Data Models
  A physical data model (PDM) helps you to analyze the tables, views, and other objects in a database, including multidimensional objects necessary for data warehousing. A PDM is more concrete than a conceptual (CDM) or logical (LDM) data model. You can model, reverse-engineer, and generate for all the most popular DBMSs.
• Creating a Data Model
  You create a new data model by selecting File > New Model.
• Customizing your Modeling Environment
  The PowerDesigner data model provides various means for customizing and controlling your modeling environment.