Index organized table and redo log it genereates

Today, OPS team raised an issue related to a program using IOT. The program generated too many archive logs thus it took more time to FTP archive logs to our DR server and apply them. 1~4 hours lag were caused by this issue. So our focus is why this program is generating so many archived logs. 

Following is my testing:

CREATE TABLE IOT_OE_ORDER_LINES
(
  LINE_ID                         NUMBER        NOT NULL PRIMARY KEY,
  ORG_ID                          NUMBER,       
  HEADER_ID                       NUMBER        NOT NULL,
  LINE_TYPE_ID                    NUMBER        NOT NULL,
  LINE_NUMBER                     NUMBER        NOT NULL,
  ORDERED_ITEM                    VARCHAR2(2000 BYTE),
  REQUEST_DATE                    DATE,
  PROMISE_DATE                    DATE,
  SCHEDULE_SHIP_DATE              DATE,
  ORDER_QUANTITY_UOM              VARCHAR2(3 BYTE),
  PRICING_QUANTITY                NUMBER,
  PRICING_QUANTITY_UOM            VARCHAR2(3 BYTE)
)
ORGANIZATION INDEX;
 

In sqlplus, set autot trace exp stat

 

SQL>
INSERT INTO IOT_OE_ORDER_LINES (   LINE_ID
  ,ORG_ID
  ,HEADER_ID
  ,LINE_TYPE_ID
  ,LINE_NUMBER
  ,ORDERED_ITEM
  ,REQUEST_DATE
  ,PROMISE_DATE
  ,SCHEDULE_SHIP_DATE
  ,ORDER_QUANTITY_UOM
  ,PRICING_QUANTITY
  ,PRICING_QUANTITY_UOM)
SELECT * FROM (SELECT LINE_ID
  ,ORG_ID
  ,HEADER_ID
  ,LINE_TYPE_ID
  ,LINE_NUMBER
  ,ORDERED_ITEM
  ,REQUEST_DATE
  ,PROMISE_DATE
  ,SCHEDULE_SHIP_DATE
  ,ORDER_QUANTITY_UOM
  ,PRICING_QUANTITY
  ,PRICING_QUANTITY_UOM
FROM OE_ORDER_LINES_ALL
ORDER BY LINE_ID
)
WHERE ROWNUM < 1000;

 

The order by line_id clause will reduce the redo size. When I tried to insert into a heap table, it generated even less redos.