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https://issues.apache.org/jira/browse/ARROW-6861?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Wes McKinney resolved ARROW-6861.
---------------------------------
Resolution: Fixed
Issue resolved by pull request 5643
[https://github.com/apache/arrow/pull/5643]
> [Python] arrow-0.15.0 reading arrow-0.14.1-output Parquet dictionary column:
> Failure reading column: IOError: Arrow error: Invalid: Resize cannot downsize
> ----------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: ARROW-6861
> URL: https://issues.apache.org/jira/browse/ARROW-6861
> Project: Apache Arrow
> Issue Type: Bug
> Components: C++, Python
> Affects Versions: 0.15.0
> Environment: debian:buster (in Docker, Linux 5.2.11-200.fc30.x86_64)
> Reporter: Adam Hooper
> Assignee: Wes McKinney
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.0.0, 0.15.1
>
> Attachments: fix-dict-builder-capacity.diff,
> parquet-written-by-arrow-0-14-1.7z
>
> Time Spent: 1h 50m
> Remaining Estimate: 0h
>
> I'll need to jump through hoops to upload the (seemingly-valid) Parquet file
> that triggers this bug. In the meantime, here's the error I get, reading the
> Parquet file with read_dictionary=true. I'll start with the stack trace:
> {{Failure reading column: IOError: Arrow error: Invalid: Resize cannot
> downsize}}
> {{#0 0x0000000000b9fffd in __cxa_throw ()}}
> {{#1 0x00000000004ce7b5 in parquet::PlainByteArrayDecoder::DecodeArrow
> (this=0x555556612e50, num_values=67339, null_count=0,
> valid_bits=0x7f39a764b780 '\377' <repeats 200 times>...,
> valid_bits_offset=748544,}}
> \{{ builder=0x555556616330) at
> /src/apache-arrow-0.15.0/cpp/src/parquet/encoding.cc:886}}
> {{#2 0x000000000046d703 in
> parquet::internal::ByteArrayDictionaryRecordReader::ReadValuesSpaced
> (this=0x555556616260, values_to_read=67339, null_count=0)}}
> \{{ at /src/apache-arrow-0.15.0/cpp/src/parquet/column_reader.cc:1314}}
> {{#3 0x00000000004a13f8 in
> parquet::internal::TypedRecordReader<parquet::PhysicalType<(parquet::Type::type)6>
> >::ReadRecordData (this=0x555556616260, num_records=67339)}}
> \{{ at /src/apache-arrow-0.15.0/cpp/src/parquet/column_reader.cc:1096}}
> {{#4 0x0000000000493876 in
> parquet::internal::TypedRecordReader<parquet::PhysicalType<(parquet::Type::type)6>
> >::ReadRecords (this=0x555556616260, num_records=815883)}}
> \{{ at /src/apache-arrow-0.15.0/cpp/src/parquet/column_reader.cc:875}}
> {{#5 0x0000000000413955 in parquet::arrow::LeafReader::NextBatch
> (this=0x555556615640, records_to_read=815883, out=0x7ffd4b5afab0) at
> /src/apache-arrow-0.15.0/cpp/src/parquet/arrow/reader.cc:413}}
> {{#6 0x0000000000412081 in parquet::arrow::FileReaderImpl::ReadColumn
> (this=0x5555566067a0, i=7, row_groups=..., out=0x7ffd4b5afab0) at
> /src/apache-arrow-0.15.0/cpp/src/parquet/arrow/reader.cc:218}}
> {{#7 0x00000000004121b0 in parquet::arrow::FileReaderImpl::ReadColumn
> (this=0x5555566067a0, i=7, out=0x7ffd4b5afab0) at
> /src/apache-arrow-0.15.0/cpp/src/parquet/arrow/reader.cc:223}}
> {{#8 0x0000000000405fbd in readParquet(std::__cxx11::basic_string<char,
> std::char_traits<char>, std::allocator<char> > const&) ()}}
> And now a report of my gdb adventures:
> In Arrow 0.15.0, when reading a particular dictionary column
> ({{read_dictionaries=true}}) with 815883 rows that was written by Arrow
> 0.14.1, {{arrow::Dictionary32Builder<arrow::BinaryType>::AppendIndices(...)}}
> is called twice (once with 493568 values, once with 254976 values); and then
> {{PlainByteArrayDecoder::DecodeArrow()}} is called. (I'm a novice; I don't
> know why this column comes in three batches.) On first {{AppendIndices()}}
> call, the buffer capacity is equal to the number of values. On second call,
> that's no longer the case: the buffer grows using
> {{BufferBuilder::GrowByFactor}}, so its capacity is 987136.
> But there's a bug: the 987136-capacity buffer is in
> {{Dictionary32Builder::indices_builder_}}; so 987136 is stored in
> {{Dictionary32Builder::indices_builder_.capacity_}}.
> {{Dictionary32Builder::capacity_}} does not change when {{AppendIndices()}}
> is called. (Dictionary32Builder behaves like a proxy for its
> {{indices_builder_}}; but its {{capacity()}} method is not virtual, so things
> are messy.)
> So {{builder.capacity_}} is 0. Then comes the final batch of 67339 values,
> via {{DecodeArrow()}}. It calls {{builder->Reserve(num_values)}}. But
> {{builder->Reserve(num_values)}} tries to increase the capacity from 0 (its
> wrong, cached value) to {{length_ + num_values}} (815883). Since
> {{indicies_builder->capacity_}} is 987136, that's a downsize – which throws
> an exception.
> The only workaround I can find: use {{read_dictionaries=false}}.
> This affects Python, too.
> I've attached a patch that fixes the issue for my file. I don't know how to
> formulate a reduction, though, so I haven't contributed unit tests. I'm also
> not certain how FinishInternal is meant to work, so this definitely needs
> expert review. (FinishInternal was _definitely_ buggy before my patch; after
> my patch it _might_ be buggy but I don't know.)
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