[jira] [Created] (ARROW-8860) [C++] Compressed Feather file with struct array roundtrips incorrectly

["Joris Van den Bossche (Jira)" <ji...@apache.org>]

Joris Van den Bossche created ARROW-8860:
--------------------------------------------

             Summary: [C++] Compressed Feather file with struct array roundtrips incorrectly
                 Key: ARROW-8860
                 URL: https://issues.apache.org/jira/browse/ARROW-8860
             Project: Apache Arrow
          Issue Type: Bug
          Components: C++
            Reporter: Joris Van den Bossche


When writing a table with a Struct typed column, this is read back with garbage values when using compression (which is the default):

{code:python}
>>>  table = pa.table({'col': pa.StructArray.from_arrays([[0,1,2], [1,2,3]], names=["f1", "f2"])})
>>>  table.column("col")
<pyarrow.lib.ChunkedArray object at 0x7f0b0c4d7458>
[
  -- is_valid: all not null
  -- child 0 type: int64
    [
      0,
      1,
      2
    ]
  -- child 1 type: int64
    [
      1,
      2,
      3
    ]
]

# roundtrip through feather
>>> feather.write_feather(table, "test_struct.feather")
>>> table2 = feather.read_table("test_struct.feather")

>>> table2.column("col")
<pyarrow.lib.ChunkedArray object at 0x7f0b0c4d7728>
[
  -- is_valid: all not null
  -- child 0 type: int64
    [
      24,
      1261641627085906436,
      1369095386551025664
    ]
  -- child 1 type: int64
    [
      24,
      1405756815161762308,
      281479842103296
    ]
]
{code}

When not using compression, it is read back correctly:

{code:python}
>>> feather.write_feather(table, "test_struct.feather", compression="uncompressed")                                                                                                                           
>>> table2 = feather.read_table("test_struct.feather")                                                                                                                                                        

>>> table2.column("col")                                                                                                                                                                                      
<pyarrow.lib.ChunkedArray object at 0x7f0b0e466778>
[
  -- is_valid: all not null
  -- child 0 type: int64
    [
      0,
      1,
      2
    ]
  -- child 1 type: int64
    [
      1,
      2,
      3
    ]
]
{code}




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