[ https://issues.apache.org/jira/browse/ARROW-8729?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
ASF GitHub Bot updated ARROW-8729: ---------------------------------- Labels: dataset dataset-dask-integration pull-request-available (was: dataset dataset-dask-integration) > [C++][Dataset] Only selecting a partition column results in empty table > ----------------------------------------------------------------------- > > Key: ARROW-8729 > URL: https://issues.apache.org/jira/browse/ARROW-8729 > Project: Apache Arrow > Issue Type: Bug > Components: C++ > Reporter: Joris Van den Bossche > Assignee: Ben Kietzman > Priority: Major > Labels: dataset, dataset-dask-integration, pull-request-available > Fix For: 1.0.0 > > Time Spent: 10m > Remaining Estimate: 0h > > Python reproducer: > {code} > import pyarrow as pa > import pyarrow.parquet as pq > import pyarrow.dataset as ds > path = "test_dataset" > table = pa.table({'part': ['a', 'a', 'b', 'b'], 'col': [1, 2, 3, 4]}) > pq.write_to_dataset(table, str(path), partition_cols=["part"]) > {code} > gives > {code} > In [38]: ds.dataset(str(path), partitioning="hive").to_table().num_rows > > > Out[38]: 4 > In [39]: ds.dataset(str(path), > partitioning="hive").to_table(columns=["part"]).num_rows > > > Out[39]: 0 > {code} > The schema correctly only includes the "part" column, but there are no rows. > cc [~bkietz] -- This message was sent by Atlassian Jira (v8.3.4#803005)