PowerExchange for Cassandra ODBC User Guide

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Tunable

You can use PowerExchange for Cassandra to specify the consistency level to use when you read data from or write data to a Cassandra database.

You can select one of the following tunable consistency levels:

ANY: Writes the data to at least one node when you write to a Cassandra database.
ONE: Writes the data to at least one replica node and reads the data from one of the closest replicas.
TWO: Writes the data to at least two replica nodes and reads the most recent data from two of the closest replicas.
Three: Writes the data to at least three replica nodes and reads the most recent data from three of the closest replicas.
QUORUM: Writes the data to the minimum required replica nodes and reads the record after the response from the minimum number of replica nodes from any data center.
LOCAL QUORUM: Writes the data to the minimum required replica nodes in the same data center and reads the record after the response from the current data center.
EACH QUORUM: Writes the data to the minimum required replica nodes in all the data centers.
ALL: Writes the data to all the replica nodes in the cluster and reads the record after the response from all the replicas.
LOCAL ONE: At least one of the replica node from the local data center must successfully acknowledge the data when you write data to a Cassandra database and must read the data from one of the closest replicas in the local data center.