[PARQUET-2316] Allow partial prebuffer in parquet FileReader

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: cpp-13.0.0
• Component/s: parquet-cpp
• Labels: pull-request-available
• Assignee: Jinpeng Zhou
• Reporter: Jinpeng Zhou
• Created: 20/Jun/23 21:49
• Updated: 12/Jul/23 22:48
• Resolved: 06/Jul/23 14:19

Description

The current FileReader can only work in  one of the two modes, coalescing (when Prebuffer is called) and non-coalescing (when Prefufer is not called), due to the if statement here

Since Prebuffer is basically caching all specified column chunks, it would raise concerns on memory usage for systems with tight memory budget. In such scenarios, one may want to Prebuffer some small chunks while being able to read the rest chunks using  BufferedInputStream. 

Issue Links

• links to: GitHub Pull Request #36192