Computer Science · Database Management Systems

Which of the following statements regarding Multiversion Concurrency Control (MVCC) are correct? I. Every write operation creates a new version of the data item rather than overwriting the existing version. II. Read operations access the most recent committed version valid at the start of the transaction and do not block writers. III. MVCC eliminates the need for any form of locking or coordination for write-write conflicts. IV. Older versions of data items require periodic garbage collection to manage storage overhead.