Logical child rules
Several rules govern the definition of the logical child segment type in a physical database.
- A logical child must have a physical and a logical parent.
- A logical child can have only one physical and one logical parent.
- A logical child is defined as a physical child in the physical database of its physical parent.
- A logical child is always a dependent segment in a physical database, and can, therefore, be defined at any level except the first level of a database.
- A logical child in its physical database cannot have a physical child defined at the next lower level in the database that is also a logical child.
- A logical child can have a physical child. However, if a logical child is physically paired with another logical child, only one of the paired segments can have physical children.