[ARROW-17648] [C++] Add ScanOptions to support projection and filter in ToProto Read

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• Labels: query-engine substrait substrait-roundtrip
• External issue URL: https://github.com/apache/arrow/issues/32889
• Assignee: Unassigned
• Reporter: Vibhatha Lakmal Abeykoon
• Created: 08/Sep/22 03:15
• Updated: 11/Jan/23 11:52

Description

When converting from an Acero plan to a Substrait plan not all scan options are fully supported. The `projection` (partial column selection) and `filter` (pushdown filtering) support needs to be added.

Ref:

 

Result<std::unique_ptr<substrait::ReadRel>> ScanRelationConverter(const std::shared_ptr<Schema>& schema, const compute::Declaration& declaration,    ExtensionSet* ext_set, const ConversionOptions& conversion_options) {  

auto read_rel = make_unique<substrait::ReadRel>();
const auto& scan_node_options = checked_cast<const dataset::ScanNodeOptions&>(*declaration.options);  
auto dataset = dynamic_cast<dataset::FileSystemDataset*>(scan_node_options.dataset.get()); 
// TODO handle here