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Posted to commits@cassandra.apache.org by Apache Wiki <wi...@apache.org> on 2011/04/14 15:58:52 UTC

[Cassandra Wiki] Update of "CassandraLimitations" by SilvereLestang

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The "CassandraLimitations" page has been changed by SilvereLestang.
The comment on this change is: Adds "maximum of column per row".
http://wiki.apache.org/cassandra/CassandraLimitations?action=diff&rev1=26&rev2=27

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  == Stuff that isn't likely to change ==
   * All data for a single row must fit (on disk) on a single machine in the cluster. Because row keys alone are used to determine the nodes responsible for replicating their data, the amount of data associated with a single key has this upper bound.
   * A single column value may not be larger than 2GB.
+  * The maximum of column per row is 2 billion.
  
  == Artifacts of the current code base ==
   * Cassandra has two levels of indexes: key and column.  But in super columnfamilies there is a third level of subcolumns; these are not indexed, and any request for a subcolumn deserializes _all_ the subcolumns in that supercolumn.  So you want to avoid a data model that requires large numbers of subcolumns.  https://issues.apache.org/jira/browse/CASSANDRA-598 is open to remove this limitation.