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https://issues.apache.org/jira/browse/ARROW-1854?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16266199#comment-16266199
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ASF GitHub Bot commented on ARROW-1854:
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wesm commented on issue #1360: ARROW-1854: [Python] Use pickle to serialize
numpy arrays of objects.
URL: https://github.com/apache/arrow/pull/1360#issuecomment-347040364
So the context is ARROW-1783 and ARROW-1784. The goal is to be able to send
pandas objects over the wire, and these frequently (anytime you have strings,
for example) have object arrays internally. So having object arrays going 3-6x
slower than pickle is a significant issue.
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> [Python] Improve performance of serializing object dtype ndarrays
> -----------------------------------------------------------------
>
> Key: ARROW-1854
> URL: https://issues.apache.org/jira/browse/ARROW-1854
> Project: Apache Arrow
> Issue Type: Improvement
> Components: Python
> Reporter: Wes McKinney
> Assignee: Wes McKinney
> Labels: pull-request-available
> Fix For: 0.8.0
>
>
> I haven't looked carefully at the hot path for this, but I would expect these
> statements to have roughly the same performance (offloading the ndarray
> serialization to pickle)
> {code}
> In [1]: import pickle
> In [2]: import numpy as np
> In [3]: import pyarrow as pa
> a
> In [4]: arr = np.array(['foo', 'bar', None] * 100000, dtype=object)
> In [5]: timeit serialized = pa.serialize(arr).to_buffer()
> 10 loops, best of 3: 27.1 ms per loop
> In [6]: timeit pickled = pickle.dumps(arr)
> 100 loops, best of 3: 6.03 ms per loop
> {code}
> [~robertnishihara] [~pcmoritz] I encountered this while working on
> ARROW-1783, but it can likely be resolved independently
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