Key Column Type
The collection metadata component that specifies the SQL data type of the column that stores the document key.
| Property | Value |
|---|---|
| Default value | VARCHAR2 |
| Allowed values |
|
| JSON collection metadata document path | keyColumn.sqlType |
Caution:
If client-assigned keys are used and the key column type is VARCHAR2 then Oracle recommends that the database character set be AL32UTF8. This ensures that conversion of the keys to the database character set is lossless.
Otherwise, if client-assigned keys contain characters that are not supported in your database character set then conversion of the key into the database character set during a read or write operation is lossy. This can lead to duplicate-key errors during insert operations. More generally, it can lead to unpredictable results. For example, a read operation could return a value that is associated with a different key from the one you expect.