[HIVE-3976] Support specifying scale and precision with Hive decimal type

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.11.0
• Fix Version/s: 0.13.0
• Component/s: Query Processor, Types
• Hadoop Flags: Incompatible change
• Assignee: Xuefu Zhang
• Reporter: Mark Grover
• Created: 01/Feb/13 22:03
• Updated: 07/Oct/15 23:14
• Resolved: 27/Oct/13 15:34

Description

HIVE-2693 introduced support for Decimal datatype in Hive. However, the current implementation has unlimited precision and provides no way to specify precision and scale when creating the table.

For example, MySQL allows users to specify scale and precision of the decimal datatype when creating the table:

CREATE TABLE numbers (a DECIMAL(20,2));

Hive should support something similar too.

Issue Links

• blocks: HIVE-5354 Decimal precision/scale support in ORC file
• depends upon: HIVE-5366 Refactor a few object inspector class to eliminate redundant information
• depends upon: HIVE-5372 Refactor TypeInfo and PrimitiveTypeEntry class hierachy to eliminate info repetition
• incorporates: HIVE-5866 Hive divide operator generates wrong results in certain cases
• incorporates: HIVE-5408 Method matching needs to be improved in NumericOpMethodResolver to suport decimal type with parameters
• incorporates: HIVE-5520 Use factory methods to instantiate HiveDecimal instead of constructors
• incorporates: HIVE-5872 Make UDAFs such as GenericUDAFSum report accurate precision/scale for decimal types
• incorporates: HIVE-5354 Decimal precision/scale support in ORC file
• incorporates: HIVE-5355 JDBC support for decimal precision/scale
• incorporates: HIVE-5356 Move arithmatic UDFs to generic UDF implementations
• incorporates: HIVE-5564 Need to accomodate table decimal columns that were defined prior to HIVE-3976
• incorporates: HIVE-5565 Limit Hive decimal type maximum precision and scale to 38
• is blocked by: HIVE-5520 Use factory methods to instantiate HiveDecimal instead of constructors
• is depended upon by: HIVE-4523 round() function with specified decimal places not consistent with mysql
• is depended upon by: HIVE-5355 JDBC support for decimal precision/scale
• is depended upon by: HIVE-5564 Need to accomodate table decimal columns that were defined prior to HIVE-3976
• is depended upon by: HIVE-5565 Limit Hive decimal type maximum precision and scale to 38
• is related to: HIVE-2693 Add DECIMAL data type
• is related to: HIVE-5520 Use factory methods to instantiate HiveDecimal instead of constructors
• relates to: HIVE-5022 Decimal Arithmetic generates NULL value
• relates to: HIVE-4844 Add varchar data type
• requires: HIVE-5548 Tests under common directory don't run as part of 'ant test'
• requires: HIVE-5706 Move a few numeric UDFs to generic implementations
• links to: https://reviews.apache.org/r/14674/