[ORC-450] [C++] Support selecting list indices without materializing list items

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.0
• Fix Version/s: 1.8.0
• Component/s: C++
• Assignee: Riza Suminto
• Reporter: Quanlong Huang
• Created: 22/Dec/18 01:36
• Updated: 03/Sep/22 22:43
• Resolved: 29/Mar/22 01:08

Description

As we don't have a type id for index field of list type, if we just want to get the list indices, we have to select the type id of the whole array, which cause unneccessary materializaion on the array item.

The offset stream is stored sperately with the content stream. We are able to just materialize the list indices.

We may need new interfaces in RowReaderOptions to specifiy this.

Issue Links

• is related to: ORC-1143 [C++] Support reading the PRESENT stream without reading the column data
• links to: GitHub Pull Request #990