HP System Dictionary/XL General Reference Manual Vol 1 (32256-90004)

3- 31
A synonym has three parts:
• The synonym name.
• The name of the entity that the synonym points to.
• The entity type of the referenced entity. A synonym implicitly has the same entity type as the entity it
references.
A synonym name must be 32 characters or less. It may not contain embedded blanks, and you cannot use
the restricted characters in Table 2-1. Because System Dictionary allows you to use entity names and
synonyms interchangeably, synonyms are subject to the same uniqueness requirements as entities. Two
synonyms of a given entity type cannot have the same name, and a synonym may not have the same name
as an entity of the same type.
A synonym points to a specific entity of a specific type. To create a synonym, the underlying entity must
already exist.
Aliases
An alias is an alternate name related to an entity’s usage in a particular subsystem. In System Dictionary,
aliases are stored in attributes of type alias. Alias attribute values are 32-byte character strings that you
can assign to any entity or relationship.
Unlike other dictionary names, an alias may contain embedded blanks. It may also contain any
combination of uppercase and lowercase characters. System Dictionary always upshifts entity names, but
aliases allow a case-sensitive name to be kept exactly as it appears in a program.
An alias may contain any special characters, even the restricted characters in Table 2-1. There are no
uniqueness requirements for aliases. An alias name can be the same as its entity name if desired, and any
number of entities and relationships can have the same alias.
When an alias is assigned to an entity, it documents an alternate name that should meet the naming
restrictions of the target subsystem (although System Dictionary does not check the name against the
subsystem restrictions).
When you assign an alias to a relationship, it provides an alternate name for the second entity in the
relationship. For example, consider the relationship CUSTOMERS contains LAST-NAME of type FORM
contains ELEMENT. You can give the relationship a VPLUS-ALIAS attribute that contains the value
LAST_NAME. In this case, the relationship-level alias documents an alternate name for the LAST-NAME
entity.
Internal Numbers
Every definition and structure in the dictionary has an internal number that System Dictionary uses to
optimize storage and retrieval. You can retrieve these numbers by dictionary intrinsics and use them in
place of names for improved performance.
Relationship Identification
A relationship does not have a name. Instead, it is identified by a list of entity names. A relationship type
is similarly identified by a list of entity type names rather than by a single name. Relationship classes