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The "WritePathForUsers" page has been changed by MichaelEdge: https://wiki.apache.org/cassandra/WritePathForUsers?action=diff&rev1=33&rev2=34 === If write request modifies materialized view === Keeping a materialized view in sync with its base table adds more complexity to the write path and also incurs performance overheads on the replica node in the form of read-before-write, locks and batch logs. 1. The replica node acquires a lock on the partition, to ensure that write requests are serialised and applied to base table and materialized views in order. - 1. The replica node reads the partition data and constructs the set of deltas to be applied to the materialized view. One insert/update/delete to the base table may result in many inserts/updates/deletes to the associated materialized view. + 1. The replica node reads the partition data and constructs the set of deltas to be applied to the materialized view. One insert/update/delete to the base table may result in one or more inserts/updates/deletes in the associated materialized view. 1. Write data to the Commit Log. 1. Create batch log containing updates to the materialized view. The batch log ensures the set of updates to the materialized view is atomic, and is part of the mechanism that ensures base table and materialized view are kept consistent. 1. Store the batch log containing the materialized view updates on the local replica node. - 1. Send materialized view updates asynchronously to the materialized view replica (note, the materialized view could be stored on the same or a different replica node to the base table). + 1. Send materialized view updates asynchronously to the materialized view replica (note, the materialized view partition could be stored on the same or a different replica node to the base table). 1. Write data to the MemTable. 1. The materialized view replica node will apply the update and return an acknowledgement to the base table replica node. 1. The same process takes place on each replica node that stores the data for the partition key.
