IF YOU LAST USED CASSANDRA 3.11, YOU MIGHT NOT RECOGNIZE IT TODAY

Summary from the TLDR Data newsletter

Apache Cassandra 5 loosens many of the constraints teams learned with 3.11, adding storage-attached indexing, unified compaction, native vector search, and built-in repair scheduling. Cassandra 6 goes further with ordered cluster metadata and cross-partition transactions, although partitioning and workload design remain fundamental.