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ASF GitHub Bot updated ARROW-8065: ---------------------------------- Labels: dataset pull-request-available (was: dataset) > [C++][Dataset] Untangle Dataset, Fragment and ScanOptions > --------------------------------------------------------- > > Key: ARROW-8065 > URL: https://issues.apache.org/jira/browse/ARROW-8065 > Project: Apache Arrow > Issue Type: Improvement > Components: C++ > Reporter: Francois Saint-Jacques > Assignee: Francois Saint-Jacques > Priority: Major > Labels: dataset, pull-request-available > > Currently: a fragment is a product of a scan; it is a lazy collection of scan > tasks corresponding to a data source which is logically singular (like a > single file, a single row group, ...). It would be more useful if instead a > fragment were the direct object of a scan; one scans a fragment (or a > collection of fragments): > # Remove {{ScanOptions}} from Fragment's properties and move it into > {{Fragment::Scan}} parameters. > # Remove {{ScanOptions}} from {{Dataset::GetFragments}}. We can provide an > overload to support predicate pushdown in FileSystemDataset and UnionDataset > {{Dataset::GetFragments(std::shared_ptr<Expression> predicate)}}. > # Expose lazy accessor to Fragment::physical_schema() > # Consolidate ScanOptions and ScanContext > This will lessen the cognitive dissonance between fragments and files since > fragments will no longer include references to scan properties. -- This message was sent by Atlassian Jira (v8.3.4#803005)