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https://issues.apache.org/jira/browse/ARROW-2227?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16395334#comment-16395334
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Antoine Pitrou edited comment on ARROW-2227 at 3/12/18 2:47 PM:
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{quote}Just wanted to mention, in case it was missed, but this example isn't a
single large 2 GiB string. Each row in the data frame is a single byte. So it
is a large array of small bytes. {quote}
Oh, I see. I had misread the example (and my crash is on a different use case
then). It's quite a weird way of storing binary strings, though? Your column is
a column of Python objects, which under the hood appear to be numpy.int64
objects... So you're paying a huge overhead because of all those objects.
(to put in perspective, I have 16 GB RAM, but creating your dataframe swaps
out...)
was (Author: pitrou):
{quote}Just wanted to mention, in case it was missed, but this example isn't a
single large 2 GiB string. Each row in the data frame is a single byte. So it
is a large array of small bytes. {quote}
Oh, I see. I had misread the example (and my crash is on a different use case
then). It's quite a weird way of storing binary strings, though? Your column is
a column of Python objects, which under the hood appear to be numpy.int64
objects... So you're paying a huge overhead because of all those objects.
> [Python] Table.from_pandas does not create chunked_arrays.
> ----------------------------------------------------------
>
> Key: ARROW-2227
> URL: https://issues.apache.org/jira/browse/ARROW-2227
> Project: Apache Arrow
> Issue Type: Bug
> Components: Python
> Affects Versions: 0.8.0
> Reporter: Chris Ellison
> Assignee: Wes McKinney
> Priority: Major
> Fix For: 0.10.0
>
>
> When creating a large enough array, pyarrow raises an exception:
> {code:java}
> import numpy as np
> import pandas as pd
> import pyarrow as pa
> x = list('1' * 2**31)
> y = pd.DataFrame({'x': x})
> t = pa.Table.from_pandas(y)
> # ArrowInvalid: BinaryArrow cannot contain more than 2147483646 bytes, have
> 2147483647{code}
> The array should be chunked for the user. As is, data frames with >2 GiB inÂ
> binary data will struggle to get into arrow.
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