Andrew Lamb created ARROW-9790:
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Summary: [Rust] [Parquet] ParquetFileArrowReader fails to decode
all pages if batches fall exactly on row group boundaries
Key: ARROW-9790
URL: https://issues.apache.org/jira/browse/ARROW-9790
Project: Apache Arrow
Issue Type: Bug
Reporter: Andrew Lamb
Assignee: Andrew Lamb
Attachments: parquet_file_arrow_reader.zip
Basically, if the parquet input file has multiple row groups, and the
{{batch_size}} specified to {{ParquetFileArrowReader}} falls exactly between
them, not all rows are read
{code}
+-----+
| RG1 |
| |
+-----+ <-- If a batch ends exactly at the end of this row group (page), RG2
is never read
+-----+
| RG2 |
| |
+-----+
{code}
A reproducer is attached. 20 values should be read by the
{{ParquetFileArrowReader}} regardless of the batch size. However, when using
batch sizes such as {{5}} or {{3}} (which fall on a boundary between row
groups) not all the rows are read.
To run the reproducer, decompress the attachment
[^parquet_file_arrow_reader.zip] and do `cargo run`
The output is as follows:
{code}
wrote 20 rows in 4 row groups to /tmp/repro.parquet
Size when reading with batch_size 100 : 20
Size when reading with batch_size 7 : 20
Size when reading with batch_size 5 : 5
{code}
The expected output is as follows (should always read 20 rows, regardless of
the batch size):
{code}
wrote 20 rows in 4 row groups to /tmp/repro.parquet
Size when reading with batch_size 100 : 20
Size when reading with batch_size 7 : 20
Size when reading with batch_size 5 : 20
{code}
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