The subject technology obtains a read timestamp of a first transaction. The subject technology performs a first read operation on a parent table associated with the first transaction to determine a set of committed versions of the parent table. The subject technology determines whether a key exists in the parent table based on the first transaction. The subject technology, in response to the key existing in the parent table, performs a first write operation on a child table. The subject technology determines whether a duplicate key exists in the child table. The subject technology, in response to determining that there is no duplicate key in the child table, determines whether there is a conflict with the key. The subject technology, in response to determining that there is no conflict with the key, performs a second write operation on a secondary index table of the child table.