[Oracle]ALL_CONS_COLUMNS

Column	Datatype	NULL	Description
OWNER	VARCHAR2(30)	NOT NULL	Owner of the constraint definition
CONSTRAINT_NAME	VARCHAR2(30)	NOT NULL	Name of the constraint definition
TABLE_NAME	VARCHAR2(30)	NOT NULL	Name of the table with the constraint definition
COLUMN_NAME	VARCHAR2(4000)		Name of the column or attribute of the object type column specified in the constraint definition
			Note: If you create a constraint on a user-defined REF column, the system creates the constraint on the attributes that make up the REF column. Therefore, the column names displayed in this view are the attribute names, with the REF column name as a prefix, in the following form: "REF_name"."attribute"
POSITION	NUMBER		Original position of the column or attribute in the definition of the object

ALL_CONS_COLUMNS을 조회하면 위에 정보를 알수 있다. 
그리고 테이블별로 CONSTRAINT_NAME 을 알수 있기 때문에 테이블의 PK 도 조회 가능하다.  

출처 : ORACLE DOCUMENT LIBRARY