Hello Cezary,    hbase> alter helps to add/modify/delete column family.  But it's not possible to rename existing column family and it will not re-write any data.   It is advisable to disable table and perform >alter and enable the table. Also, if you modify properties like TTL, versions it will applicable for new writes and for existing data it will take effect only after >major_compact <table>   Hope that helps!  ... View more