Lock row for access : In insert-Select - response (5) by FarhanArif

Locking Row for Access only works (locks only a limited number of rows in a table) when there is an equality condition on a UPI or NUPI in a WHERE clause. This is because it is generally a row hash level lock.
Example:
LOCKING ROW FOR ACCESS
SEL * FROM TAB1
WHERE  COL1 = 1
In the case where there is no WHERE clause, Locking Row for Access is automatically converted to a Table Level lock (LOCKING TABLE FOR ACCESS)