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The "Hive/PartitionedViews" page has been changed by JohnSichi. http://wiki.apache.org/hadoop/Hive/PartitionedViews?action=diff&rev1=9&rev2=10 -------------------------------------------------- = Approaches = 1. One possible approach mentioned in [[https://issues.apache.org/jira/browse/HIVE-1079|HIVE-1079]] is to infer view partitions automatically based on the partitions of the underlying tables. A command such as SHOW PARTITIONS could then synthesize virtual partition descriptors on the fly. This is fairly easy to do for use case #1, but potentially very difficult for use cases #2 and #3. So for now, we are punting on this approach. - 1. Instead, per [[https://issues.apache.org/jira/browse/HIVE-1941|HIVE-1941]], we will require users to explicitly declare view partitioning as part of CREATE VIEW, and explicitly manage partition metadata via ALTER VIEW {ADD|DROP} PARTITION. This allows all of the use cases to be satisfied (while placing more burden on the user, and taking up more metastore space). With this approach, there is no real connection between view partitions and underlying table partitions; it's even possible to create a partitioned view on an unpartitioned table, or to have data in the view which is not covered by any view partition. One downside here is that a UI will not be able to show last access time and physical information such as file size when browsing available partitions. (And stats won't work without an explicit ANALYZE.) + 1. Instead, per [[https://issues.apache.org/jira/browse/HIVE-1941|HIVE-1941]], we will require users to explicitly declare view partitioning as part of CREATE VIEW, and explicitly manage partition metadata via ALTER VIEW {ADD|DROP} PARTITION. This allows all of the use cases to be satisfied (while placing more burden on the user, and taking up more metastore space). With this approach, there is no real connection between view partitions and underlying table partitions; it's even possible to create a partitioned view on an unpartitioned table, or to have data in the view which is not covered by any view partition. One downside here is that a UI will not be able to show last access time and physical information such as file size when browsing available partitions. (In theory, stats could work via an explicit ANALYZE, but analyzing a view would need some work.) = Syntax =
