Other Restrictions
The Apache Hive server has the following restrictions:
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Column values and parameters are always nullable
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No ROWID support
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No support for synonyms
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Primary and foreign keys are not supported.
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The length of a SQL string is limited to 2 GB.
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Support for indexes is incomplete.
The ACID operations have the following restrictions:
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Hive ACID operations are supported only on servers that are configured to use them
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Single-table operations for Updates and Deletes are supported only for tables marked as transactional
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Hive ACID operations do not currently support Begin, Commit, or Rollback statements