Table Oracle PLSQL Tutorial

By default, a constraint is enabled when you create it.
You can disable a constraint when you create it by adding DISABLE to the end of the CONSTRAINT clause.

SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> ALTER TABLE myTable
  2  ADD CONSTRAINT uq UNIQUE (id) DISABLE;
Table altered.
SQL>
SQL> ALTER TABLE myTable
  2  DISABLE CONSTRAINT uq;
Table altered.
SQL>
SQL> drop table myTable
  2  /
Table dropped.
SQL>