This document discusses adding ACID transaction support to Hive to allow for updating, deleting, and inserting rows. It describes how HDFS storage is organized using base and delta files. Transactions are managed through a new transaction manager that uses the metastore database. Locking is implemented to control concurrent access. Streaming ingest is supported through a new interface that allows small batches to be written and committed. The goal is to support SQL commands like UPDATE and DELETE while providing scalable reads and writes through compactions.