Try using ADD_SECONDS function as below:
SELECT ADD_SECONDS (TO_TIMESTAMP('2017-07-15 02:17:15'), 0.1) FROM TEST
This will add seconds as fraction value as requested. Below is syntax and example:
ADD_SECONDS (t, n)
Computes the time t plus n seconds.
SELECT ADD_SECONDS (TO_TIMESTAMP ('2012-01-01 23:30:45'), 60*30) "add seconds" FROM DUMMY;
To know more about ADD_SECONDS function, you can also refer this link:
To know more about SQL functions in SAP HANA system, you can also refer our HANA tutorial: