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The "Hive/Locking" page has been changed by NamitJain. http://wiki.apache.org/hadoop/Hive/Locking?action=diff&rev1=1&rev2=2 -------------------------------------------------- = Use Cases = + Concurrency support (http://issues.apache.org/jira/browse/HIVE-1293) is a must in databases and their usecases are well understood. At a minimum, we want to support concurrent readers and writers whenever possible. + It would be useful to add a mechanism to discover the current locks which have been acquired. - 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 = - - At a minimum, we want to - - * add queryable view support at the SQL language level (specifics of the scoping are under discussion in the Issues section below) - * updatable views will not be supported - * make sure views and their definitions show up anywhere tables can currently be enumerated/searched/described - * where relevant, provide additional metadata to allow views to be distinguished from tables - - 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 =
