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A physical data diagram provides a graphical view of your database structure, and helps you analyze its tables (including their columns, indexes, and triggers), views, and procedures, and the references between them.

To create a physical diagram in an existing PDM, right-click the model in the Browser and select Start of the navigation path New Next navigation step Physical Diagram End of the navigation path. To create a new model, select Start of the navigation path File Next navigation step New Model End of the navigation path, choose Physical Data Model as the model type and Physical Diagram as the first diagram, and then click OK.

In the following example, the Employee table is shown in relation to the Team, Division, Material, Task, and Project tables:
PDM Diagram Example

The following objects can be created in a physical diagram:

Tool

Description

Table - A collection of rows (records) that have associated columns (fields). See Tables (PDM).

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Column - A data structure that contains an individual data item within a row (record), model equivalent of a database field. See Columns (PDM).

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Primary Key - A column or columns whose values uniquely identify each row in a table, and are designated as the primary identifier of each row in the table. See Primary, Alternate, and Foreign Keys (PDM).

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Alternate Key - A column or columns whose values uniquely identify each row in a table, and which is not a primary key. See Primary, Alternate, and Foreign Keys (PDM).

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Foreign Key - A column or columns whose values depend on and migrate from a primary or alternate key in another table. See Primary, Alternate, and Foreign Keys (PDM).

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Index - A data structure associated with one or more columns in a table, in which the column values are ordered in such a way as to speed up access to data. See Indexes (PDM).

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Default - [certain DBMSs] A default value for a column. See Defaults (PDM).

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Domain - Defines valid values for a column. See Domains (CDM/LDM/PDM).

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Sequence - [certain DBMSs] Defines the form of incrementation for a column. See Sequences (PDM).

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Abstract data type [certain DBMSs] A user-defined data type. See Abstract Data Types (PDM).

Reference - A link between a primary or an alternate key in a parent table, and a foreign key of a child table. Depending on its selected properties, a reference can also link columns that are independent of primary or alternate key columns. See References (PDM).

View - A data structure that results from a SQL query and that is built from data in one or more tables. See Views (PDM).

View reference - A link between a table and a view. See View References (PDM).

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Trigger - A segment of SQL code associated with a table or a view. See Triggers (PDM).

Procedure - A precompiled collection of SQL statements stored under a name in the database and processed as a unit. See Stored Procedures and Functions (PDM).

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Database - The database of which the PDM is a representation. See Creating a Database in the Model.

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Storage - A partition on a storage device. See Tablespaces and Storages (PDM).

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Tablespace - A partition in a database. See Tablespaces and Storages (PDM).

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User - A person who can log in or connect to the database. See Users, Groups, and Roles (PDM).

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Role - A predefined user profile. See Users, Groups, and Roles (PDM).

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Group - Defines privileges and permissions for a set of users. See Users, Groups, and Roles (PDM).

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Synonym - An alternative name for various types of objects. See Synonyms (PDM).

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Web service - A collection of SQL statements stored in a database to retrieve relational data in HTML, XML, WSDL or plain text format, through HTTP or SOAP requests. See Web Services (PDM).

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Web operation - A sub-object of a Web service containing a SQL statement and displaying Web parameters and result columns. See Web Operations (PDM).

In this section:
    Tables (PDM)
    A table is used to store data in a set of columns. Each record in the table is represented as a row, which is uniquely identified by the values in its primary key column or columns.
    Columns (PDM)
    A column is a set of values of a single type in a table. Each row of the table contains one instance of each column. Each table must have at least one column, which must have a name and code and to which you can assign a data type, either directly, or via a domain.
    Primary, Alternate, and Foreign Keys (PDM)
    A key is a column, or a combination of columns, that uniquely identifies a row in a table. Each key can generate a unique index or a unique constraint in a target database.
    Indexes (PDM)
    An index is a data structure associated with one or more columns ordered by the column values. Indexes are typically created for columns that you are frequently searched on to improve response times. Most types of index are more effective when applied to columns with high cardinality.
    Views (PDM)
    A view is a query that provides access to all or a subset of the data in a table or multiple tables connected by joins. Views do not copy the data from their underlying tables and are updated when data in those tables changes. Views can reference other views, can order or filter data as necessary, and may be indistinguishable from tables for users accessing them.
    Triggers (PDM)
    A trigger is a segment of SQL code associated with a table or a view, which is invoked automatically whenever there is an attempt to modify data in the associated table or view with an insert, delete, or update command. A DBMS trigger is not associated with any table or view, and fires on modifications to the database structure itself, such as the creation or dropping of a table or events like startup, shutdown, login etc. You can use triggers to enforce referential integrity (where declarative constraints are not sufficient) and to implement sequences for columns.
    Stored Procedures and Functions (PDM)
    You can define stored procedures and functions for any DBMS that supports them.
    Users, Groups, and Roles (PDM)
    A user is a database object that identifies a person who can login or connect to the database. Groups and roles are used to simplify the granting of rights to users, as privileges and permissions granted to a group or role are inherited by users who belong to that group or incarnate that role.
    Synonyms (PDM)
    Synonyms are alternative names for various types of database object, which can be used to mask the name and owner of the object, provide location transparency for remote objects of a distributed database, and simplify SQL statements for database users.
    Defaults (PDM)
    Default objects are named values that can be assigned to columns or domains. Defaults are available for selection from the Default list on the Check Parameters tab of column and domain property sheets. Defaults are not supported by all DBMSs.
    Domains (CDM/LDM/PDM)
    Domains allow you to group together a data type, length, precision, mandatoriness, check parameters, and business rules to standardize their application to a set of columns and entity attributes. You can define domains for columns of type ID, name, address, or any other kind of data whose use you want to standarize across multiples columns or attributes in your model.
    Sequences (PDM)
    Sequences are auto-incremented columns that allow you to define complex incrementations. Sequences are available for selection from the Sequence list on the General tab of column property sheets. Sequences are not supported by all DBMSs.
    Abstract Data Types (PDM)
    An abstract data type (ADT) is a user-defined data type which can encapsulate a data set and functions that can be performed on the data. Abstract data types are not supported by all DBMSs.
    References (PDM)
    A reference is a link between a parent table and a child table, which defines a referential integrity constraint between column pairs for a primary or alternate key and a foreign key, or between user-specified columns. Each column pair is linked by a join, and each reference can contain one or more joins. Each value in the child table column is equal to the value in the parent table column.
    View References (PDM)
    A view reference is a link between a parent table or view and a child table or view, which defines the joins between the parent and child columns. View references are not generated to the database
    Business Rules (CDM/LDM/PDM)
    A business rule can represent a government-imposed law, a customer requirement, or an internal guideline. They may start as simple observations, such as "customers call toll-free numbers to place orders", and develop into more detailed expressions during the design process such as what information a customer supplies when placing an order or how much a customer can spend based on a credit limit.
    Lifecycles (PDM)
    A lifecycle allows you to model the movement of data from expensive, rapid storage, through various forms of cheaper slower storage as the data ages and access requirements diminish. The period during which data remain in each kind of storage are modeled as phases, which are associated with tablespaces.
    Tablespaces and Storages (PDM)
    Tablespaces and storages are generic objects used to represent physical locations (in named partitions) of tables and indexes in a database or storage device. A tablespace is a partition in a database. A storage is a partition on a storage device. Some DBMSs, allow a tablespace to use a specified storage in its definition.
    Web Services (PDM)
    Web services are applications stored on web servers that are accessed through standard web protocols (HTTP, SOAP) and data formats (HTML, XML...), whatever the systems and programming languages. PowerDesigner supports modeling for both the SOAP protocol, in which queries are encapsulated into services, and HTTP, where operations are invoked directly.