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The "FAQ" page has been changed by JonathanEllis: https://wiki.apache.org/cassandra/FAQ?action=diff&rev1=171&rev2=172 Comment: Don't batch damn it * [[#iter_world|How can I iterate over all the rows in a ColumnFamily?]] * [[#gui|Is there a GUI admin tool for Cassandra?]] * [[#clustername_mismatch|Cassandra says "ClusterName mismatch: oldClusterName != newClusterName" and refuses to start]] - * [[#batch_mutate_atomic|Are batch_mutate operations atomic?]] + * [[#batch_mutate_atomic|Are batch operations atomic?]] + * [[#batch_bulkload|Will batching my operations speed up my bulk load?]] * [[#hadoop_support|Is Hadoop (i.e. Map/Reduce, Pig, Hive) supported?]] * [[#multi_tenant|Can a Cassandra cluster be multi-tenant?]] * [[#using_cassandra|Who is using Cassandra and for what?]] @@ -248, +249 @@ <<Anchor(batch_mutate_atomic)>> - == Are batch_mutate operations atomic? == + == Are batchoperations atomic? == Since Cassandra 1.2, CQL batches are atomic by default (http://www.datastax.com/dev/blog/atomic-batches-in-cassandra-1-2). Thrift API users must call atomic_batch_mutate instead of batch_mutate if they want this behavior. + + <<Anchor(batch_bulkload)>> + + == Will batching my operations speed up my bulk load? == + + '''NO.''' Using batches to load data will just add "spikes" of latency. Don't do this. Use asynchronous INSERTs instead, or use true BulkLoading. + + (Minor exception: batching updates to a single partition can be a Good Thing. But never ever blindly batch everything!) <<Anchor(hadoop_support)>>
