You use the key category to define whether the internal table defined by the table type can contain only records with a unique key, or whether the key can have duplicates.
You can define the following key categories:
This table type can contain only records with a unique key.
A table with this table type can also contain records that do not have different keys for the table type.
The key category is unique or non-unique. This defines a generic table type .
Only certain combinations of access mode and key category are allowed. These are listed in the following table.
Access Mode |
Key category |
Not Specified |
Not specified |
Index Table |
Not specified |
Standard Table |
Non-Unique |
Sorted Table |
Unique, Non-Unique or Not specified |
Hashed Table |
Unique |
If the primary key of a standard table or hash table is not specified, you have to select key category Not specified.