[HIVE-5762] Implement vectorized support for the DECIMAL data type

• Type: Sub-task
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Assignee: Eric N. Hanson
• Reporter: Eric N. Hanson
• Created: 06/Nov/13 18:27
• Updated: 17/Dec/13 23:39

Description

Add support to allow queries referencing DECIMAL columns and expression results to run efficiently in vectorized mode. Include unit tests and end-to-end tests.

Before starting or at least going very far, please write design specification (a new section for the design spec attached to HIVE-4160) for how support for the different DECIMAL types should work in vectorized mode, and the roadmap, and have it reviewed.

It may be feasible to re-use LongColumnVector and related VectorExpression classes for fixed-point decimal in certain data ranges. That should be at least considered to get faster performance and save code. For unlimited precision DECIMAL, a new column vector subtype may be needed, or a BytesColumnVector could be re-used.

Issue Links

• contains: HIVE-6051 Create DecimalColumnVector and a representative VectorExpression for decimal
• contains: HIVE-5918 int / int division does not vectorize due to type checks
• depends upon: HIVE-6017 Contribute Decimal128 high-performance decimal(p, s) package from Microsoft to Hive
• is duplicated by: HIVE-5937 vectorization support for decimal