Hi Ravi,
I have solve the issue, in order to update fuzzy field to NULL, in create table definition must set the field as DEFAULT NULL as following:
"HOUSE_NO" TEXT FUZZY SEARCH INDEX ON FAST PREPROCESS ON DEFAULT NULL
Then, we can simply update the fuzzy field to NULL if condition meet:
UPDATE schema.test
SET HOUSE_NO = NULL WHERE HOUSE_NO LIKE '<NULL>'
Please note that cannot set where condition as WHERE HOUSE_NO = '<NULL>', otherwise you will get error "inconsistent datatype - lob type comparison".
Regards,
Alexender