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