Ejournal transcoding

摘要

A journaled database system may comprise data nodes that maintain a collection of data structured in accordance with a schema. A change to the schema may be applied by a journal module while a journal consumer continues to operate using a prior version of the schema. A buffer may be formed and have stored therein records describing state change instructions according to the prior view of the schema. An index of correspondence between the records in the buffer and in the source journal may be maintained.