ContextQMD
Back to Scylladb

SSTable Version Support

docs/architecture/sstable/_common/sstable_what_is.rst

latest1.2 KB
Original Source

:term:Sorted Strings Table (SSTable)<SSTable> is the persistent file format used by ScyllaDB and Apache Cassandra. SSTable is saved as a persistent, ordered, immutable set of files on disk. Immutable means SSTables are never modified; they are created by a MemTable flush and are deleted by a compaction. The location of ScyllaDB SSTables is specified in scylla.yaml data_file_directories parameter (default location: /var/lib/scylla/data).

SSTable 3.x is more efficient and requires less disk space than the SSTable 2.x.

SSTable Version Support

.. list-table:: :widths: 50 50 :header-rows: 1

    • SSTable Version
    • ScyllaDB Version
    • 3.x ('ms')
    • 2025.4 and above
    • 3.x ('me')
    • 2022.2 and above
    • 3.x ('md')
    • 2021.1

  • The supported formats are me and ms.

  • The md format is used only when upgrading from an existing cluster using md. The sstable_format parameter is ignored if it is set to md.

  • Note: The sstable_format parameter specifies the SSTable format used for writes. The legacy SSTable formats (ka, la, mc) remain supported for reads, which is essential for restoring clusters from existing backups.