A primary key is the column or columns that contain values
that uniquely identify each row in a table. A database table must
have a primary key for Optim to insert,
update, restore, or delete data from a database table. Optim uses
primary keys that are defined to the database. However, you can also
define primary keys to supplement those in the database.
A primary key is needed:
- In any table that is visited more than once in a
process, for example, a child table that has two or more parent tables
referenced in the Access Definition.
- To enable the Point and Shoot feature for a Start
Table. For details, see Edit Point and Shoot List.
Note: If a primary key is not defined and is required to perform a
specific task, an error message appears. Use the Primary Key Editor
to create the necessary primary key.
Types of Optim Primary
Keys
You can define two types of primary
keys that are stored in the Optim™ Directory:
- An Explicit primary key applies to a single
table.
- A Generic primary key applies to any tables
that have the same base name, column names, and attribute specifications,
but different Creator IDs.
There is no difference in function or appearance
between generic and explicit primary keys. However, if a table has
keys of both types, the explicit primary key is used.
Naming Conventions
The
fully qualified name of a primary key is the same as the fully qualified
name of the database table for which it is defined. This name consists
of: dbalias.creatorid.tablename.
- dbalias
- Alias that identifies the database where the table
resides (1 to 12 characters).
- creatorid
- Creator ID assigned to the table (1 to 64 characters).
- tablename
- Base table name (1 to 64 characters).
Note: - The combined total length of columns for a primary key is limited
to 3584 bytes.
- When Object Security is enabled, the second and third parts of
a primary key (i.e., the creatorid and tablename)
are restricted to a combined total of 64 characters.
- When Object Security is not enabled, each of those parts may consist
of up to 64 characters. See the Installation and Configuration
Guide for detailed information about Object Security.
Contents
This
section explains how to create and maintain explicit and generic primary
keys defined to the Optim Directory,
including how to:
- Create and edit an explicit or generic primary key.
- Create a primary key from a unique index.
- Convert a primary key to a generic primary key.