[jira] [Created] (ARROW-3978) [C++] Implement hashing, dictionary-encoding for StructArray
Wes McKinney created ARROW-3978:
Summary: [C++] Implement hashing, dictionary-encoding for StructArray
Project: Apache Arrow
Issue Type: New Feature
Reporter: Wes McKinney
Fix For: 0.13.0
This is a central requirement for hash-aggregations such as
GROUP BY expr1, expr2, ...
The materialized keys in the GROUP BY section form a struct, which can be incrementally hashed to produce dictionary codes suitable for computing aggregates or any other purpose.
There are a few subtasks related to this, such as efficiently constructing a record (that can be hashed quickly) to identify each "row" in the struct. Maybe we should start with that first
This message was sent by Atlassian JIRA