[ https://issues.apache.org/jira/browse/ARROW-7545?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Neal Richardson updated ARROW-7545: ----------------------------------- Fix Version/s: 0.16.0 > [C++] [Dataset] Scanning dataset with dictionary type hangs > ----------------------------------------------------------- > > Key: ARROW-7545 > URL: https://issues.apache.org/jira/browse/ARROW-7545 > Project: Apache Arrow > Issue Type: Bug > Components: C++ - Dataset > Reporter: Joris Van den Bossche > Priority: Critical > Labels: dataset > Fix For: 0.16.0 > > > I assume it is an issue on the C++ side of the datasets code, but reproducer > in Python. > I create a small parquet file with a single column of dictionary type. > Reading it with {{pq.read_table}} works fine, reading it with the datasets > machinery hangs when scanning: > {code:python} > import pandas as pd > import pyarrow as pa > import pyarrow.parquet as pq > df = pd.DataFrame({'a': pd.Categorical(['a', 'b']*10)}) > arrow_table = pa.Table.from_pandas(df) > filename = "test.parquet" > pq.write_table(arrow_table, filename) > from pyarrow.fs import LocalFileSystem > from pyarrow.dataset import ParquetFileFormat, Dataset, > FileSystemDataSourceDiscovery, FileSystemDiscoveryOptions > filesystem = LocalFileSystem() > format = ParquetFileFormat() > options = FileSystemDiscoveryOptions() > discovery = FileSystemDataSourceDiscovery( > filesystem, [filename], format, options) > inspected_schema = discovery.inspect() > dataset = Dataset([discovery.finish()], inspected_schema) > # dataset.schema works fine and gives correct schema > dataset.schema > scanner_builder = dataset.new_scan() > scanner = scanner_builder.finish() > # this hangs > scanner.to_table() > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)