[DRILL-3209] [Umbrella] Plan reads of Hive tables as native Drill reads when a native reader for the underlying table format exists

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Component/s: Query Planning & Optimization, Storage - Hive
• Assignee: Venki Korukanti
• Reporter: Jason Altekruse
• Created: 28/May/15 22:49
• Updated: 01/Oct/15 23:27
• Resolved: 01/Oct/15 23:27

Description

All reads against Hive are currently done through the Hive Serde interface. While this provides the most flexibility, the API is not optimized for maximum performance while reading the data into Drill's native data structures. For Parquet and Text file backed tables, we can plan these reads as Drill native reads. Currently reads of these file types provide untyped data. While parquet has metadata in the file we currently do not make use of the type information while planning. For text files we read all of the files as lists of varchars. In both of these cases, casts will need to be injected to provide the same datatypes provided by the reads through the SerDe interface.

Issue Links

• is depended upon by: DRILL-3678 Plan generating for Drill on Hive takes huge java heap size
• links to: Review Board Link

Sub-Tasks

• Enhance HiveDrillNativeParquetScan and related classes to support multiple formats.: Open