Cloudera Docs

READ Support for FULL ACID ORC Tables

FULL ACID v2 transactional tables are readable in Impala without modifying any configurations. You must have Cloudera Runtime 7.2.2 or higher and have connection to Hive Metastore server in order to READ from FULL ACID tables.

There are two types of transactional tables available with Hive ACID.

  • INSERT-ONLY
  • FULL ACID

Until this release, Impala in CDP supported INSERT-ONLY transactional tables allowing both READ and WRITE operations. The latest version of Impala in CDP now also supports READ of FULL ACID ORC tables.

By default tables created in Impala are INSERT-ONLY managed tables whereas the default tables in Hive are managed tables that are FULL-ACID.

Limitations

  • Impala cannot CREATE or WRITE to FULL ACID transactional tables yet. You can CREATE and WRITE FULL ACID transactional tables with transaction scope at the row level via HIVE and use Impala to READ these tables.
  • Impala does not support ACID v1.