[ARROW-6077] [C++][Parquet] Build logical schema tree mapping Arrow fields to Parquet schema levels

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.15.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/22477
• Assignee: Wes McKinney
• Reporter: Wes McKinney
• Created: 31/Jul/19 02:53
• Updated: 11/Jan/23 07:44
• Resolved: 02/Aug/19 01:53

Description

In several places in cpp/src/parquet/arrow, the FromParquetSchema function is used to construct fields using a filtered "view" of the Parquet schema. This is a hack caused by the lack of some kind of a "schema tree" which maps Parquet concepts to Arrow Field objects.

One manifestation of this issue is that I was unable to implement dictionary encoded subfields in cases like list<string>, where you want the inner field to be dictionary-encoded.

Patch forthcoming

Issue Links

• is depended upon by: ARROW-3325 [Python] Support reading Parquet binary/string columns directly as DictionaryArray
• links to: GitHub Pull Request #4971