CTAS query in Oracle for Index Organized tables - oracle

Question

Is it possible to write a CTAS (create table as select ...) query in Oracle to create Index Organized tables ?
Have looked on the net and tried a few versions of the CTAS, but unable to find a working sample/quide query.

Answer 1

Short answer: yes.
Example, based on the JOB_HISTORY table:
table JOB_HISTORY
SQL> select * from hr.job_history ;
EMPLOYEE_ID START_DATE END_DATE JOB_ID DEPARTMENT_ID
102 13-JAN-93 24-JUL-98 IT_PROG 60
101 21-SEP-89 27-OCT-93 AC_ACCOUNT 110
101 28-OCT-93 15-MAR-97 AC_MGR 110
201 17-FEB-96 19-DEC-99 MK_REP 20
114 24-MAR-98 31-DEC-99 ST_CLERK 50
122 01-JAN-99 31-DEC-99 ST_CLERK 50
200 17-SEP-87 17-JUN-93 AD_ASST 90
176 24-MAR-98 31-DEC-98 SA_REP 80
176 01-JAN-99 31-DEC-99 SA_MAN 80
200 01-JUL-94 31-DEC-98 AC_ACCOUNT 90
Query (for generating sample data)
-- every employee must do every job (only for a day at a time ...)
select E.employee_id, J.job_id
, sysdate - ( row_number() over ( order by E.employee_id, J.job_id ) ) dt
from (
select unique employee_id from hr.job_history
) E cross join (
select unique job_id from hr.job_history
) J ;
--
EMPLOYEE_ID JOB_ID DT
101 AC_ACCOUNT 10-FEB-20
101 AC_MGR 09-FEB-20
101 AD_ASST 08-FEB-20
101 IT_PROG 07-FEB-20
101 MK_REP 06-FEB-20
101 SA_MAN 05-FEB-20
101 SA_REP 04-FEB-20
101 ST_CLERK 03-FEB-20
102 AC_ACCOUNT 02-FEB-20
102 AC_MGR 01-FEB-20
...
200 ST_CLERK 25-DEC-19
201 AC_ACCOUNT 24-DEC-19
201 AC_MGR 23-DEC-19
201 AD_ASST 22-DEC-19
201 IT_PROG 21-DEC-19
201 MK_REP 20-DEC-19
201 SA_MAN 19-DEC-19
201 SA_REP 18-DEC-19
201 ST_CLERK 17-DEC-19
--56 rows selected.
CTAS
-- heap organized table
create table heap_empjobs (
employee_id, job_id, dt
, constraint heap_empjobs_pk primary key( employee_id, job_id, dt )
)
as
select E.employee_id, J.job_id
, sysdate - ( row_number() over ( order by E.employee_id, J.job_id ) ) dt
from (
select unique employee_id from hr.job_history
) E cross join (
select unique job_id from hr.job_history
) J
;
-- Table created.
-- index organized table
create table iot_empjobs (
employee_id, job_id, dt
, constraint iot_pk primary key( employee_id, job_id, dt ) -- also works without naming the constraint
)
organization index
as
select E.employee_id, J.job_id
, sysdate - ( row_number() over ( order by E.employee_id, J.job_id ) ) dt
from (
select unique employee_id from hr.job_history
) E cross join (
select unique job_id from hr.job_history
) J
;
-- Table created.
Checks
select count(*) from heap_empjobs ;
COUNT(*)
56
select count(*) from iot_empjobs ;
COUNT(*)
56
select table_name, nvl( to_char( num_rows ), 'no rows!' ) rowcount
from user_tables
where table_name in ('HEAP_EMPJOBS', 'IOT_EMPJOBS') ;
TABLE_NAME ROWCOUNT
HEAP_EMPJOBS 56
IOT_EMPJOBS no rows!
Tested with Oracle 18c and 11g (see dbfiddle).