[DRILL-7574] Generalize projection parser

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.17.0
• Fix Version/s: 1.18.0
• Labels: ready-to-commit
• Assignee: Paul Rogers
• Reporter: Paul Rogers
• Reviewer: Bohdan Kazydub
• Created: 08/Feb/20 07:04
• Updated: 21/Feb/20 15:50
• Resolved: 21/Feb/20 15:50

Description

EVF contains a bit of code called the"projection parser": it takes a projection list and converts it into a form useful for scan projection. The prior version handled single-level arrays, such as needed for the `columns` column in the text reader. For JSON, we must handle arbitrary column structures such as:

a, a.b, a[1], a[1][2], a.[1][2].b

Adding the DICT type means that we must be a bit more general in the parser. This ticket fixes these issues.

Issue Links

• is part of: DRILL-6953 Merge row set-based JSON reader
• links to: GitHub Pull Request #1974