In Cassandra, both
INSERT statements are write operations, which means that these operation don't do any reading before writing. This implies that, if we're executing an
UPDATE operation on a primary key and the row for that primary key doesn't exist,
UPDATE will insert a new row.
Similarly, if we're performing an
INSERT operation and the row mentioned in the
INSERT operation identified by the primary key already exists in the database, that row will be overwritten by our
This is why we call them
UPSERT operations as well.
UPSERT operations are valid operations in Cassandra and won't throw any errors.