What is a Composite Primary Key?

A Composite Primary key is Primary key What a primary key, which is defined by having multiple fields (columns) in it.  Like a Primary Key what a composite Primary Key is depends on the database.  Essentially a Composite Primary Key:

• Is a combination of Fields (columns) which uniquely identifies every row.
• Is an index in database systems which use indexes for optimization
• Is a type of table constraint
• Is applied with a data definition language (DDL) alter command
• And may define parent-Child relationship between tables

Related References

• Database – What is a Primary Key?
• Data Modeling – Fact Table Effective Practices
• Data Modeling – Dimension Table Effective Practices
• Netezza / PureData Table Documentation Practices
• Database Table Field Ordering Effective Practices
• What is DDL?
• Netezza/ PureData – how to add a primary key