Hello:

In Version "15.0.0.2050 (64 bit)" when we have an immutable table and the DDL is generated, it is not put into the script.

Example:

SQL Query
create immutable table it_t1 (
  id            number,
  fruit         varchar2(20),
  quantity      number,
  created_date  date,
  constraint it_t1_pk primary key (id)
)
no drop until 0 days idle
no delete until 16 days after insert;

PL/SQL Developer script:

SQL Query
-- Create table
create table IT_T1
(
  id           NUMBER not null,
  fruit        VARCHAR2(20),
  quantity     NUMBER,
  created_date DATE
)
tablespace DATOS
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );
-- Create/Recreate primary, unique and foreign key constraints 
alter table IT_T1
  add constraint IT_T1_PK primary key (ID)
  using index 
  tablespace DATOS
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );


-------------------------------
Elias F.M.