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The "Hive/ViewDev" page has been changed by JohnSichi. http://wiki.apache.org/hadoop/Hive/ViewDev?action=diff&rev1=9&rev2=10 -------------------------------------------------- = Use Cases = - Views are a standard DBMS feature and their uses are well understood. A typical use case might be to create an interface layer with a consistent entity/attribute naming scheme on top of an existing set of inconsistently named tables, without having to cause disruption due to direct modification of the tables. More advanced use cases would involve predefined filters, joins, aggregations, etc for simplifying query construction by end users, as well as sharing common definitions within ETL pipelines. + Views (http://issues.apache.org/jira/browse/HIVE-972) are a standard DBMS feature and their uses are well understood. A typical use case might be to create an interface layer with a consistent entity/attribute naming scheme on top of an existing set of inconsistently named tables, without having to cause disruption due to direct modification of the tables. More advanced use cases would involve predefined filters, joins, aggregations, etc for simplifying query construction by end users, as well as sharing common definitions within ETL pipelines. = Scope = @@ -16, +16 @@ Beyond this, we may want to * expose metadata about view definitions and dependencies (at table-level or column-level) in a way that makes them consumable by metadata-driven tools + + = Syntax = + + {{{ + CREATE VIEW [IF NOT EXISTS] view_name [ (column_name [COMMENT column_comment], ...) ] + [COMMENT table_comment] + AS SELECT ... + + DROP VIEW view_name + }}} = Implementation Sketch =
