2899060 - A query -- nothing 'From Clause' , kind of CIS operation-- returns long performance. - SAP IQ

Following Query pattern -- nothing From clause -- returned long performance delay. 
( 'Where clause' in this query has nothing to do with this performance issue at all )

INSERT into Test_TB (COL1, TradeDate, COL3, Version, COL4, COL5, COL6, COL7, COL8, COL9,COL10,COL11, COL12, COL13)
SELECT 'ABC','20200228','B020',10,'ABC','AUD','ALL','F','33','D','R','A',96000,''
WHERE not exists (SELECT 1 FROM Test_TB WHERE COL1 = 'ABC'
     and TradeDate = '20200228' and COL3 = 'B020'
     and Version = 10 and COL4 = 'ABC' and COL5 = 'AUD' ) ;

But below similar query pattern returned expected performance,

SELECT 'ABC','20200228','B020',10,'ABC','AUD','ALL','F','33','D','R','A',96000,''
WHERE not exists (SELECT 1 FROM Test_TB WHERE COL1 = 'ABC'
and TradeDate = '20200228' and COL3 = 'B020'
and Version = 10 and COL4 = 'ABC' and COL5 = 'AUD' );

,or,

INSERT into Test_TB (COL1, TradeDate, COL3, Version, COL4, COL5, COL6, COL7, COL8,
COL9,COL10,COL11, COL12, COL13)
SELECT 'ABC','20200228','B020',10,'ABC','AUD','ALL','F','33','D','R','A',96000,''

SAP IQ16.1

CIS, Pass through, SA operation, SA Table, From Clause, , KBA , BC-SYB-IQ , Sybase IQ , How To