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https://issues.apache.org/jira/browse/ARROW-6774?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17205061#comment-17205061
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Sietse Brouwer commented on ARROW-6774:
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I'm not sure what test data [~alippai] used, so I used a test data set with
500k rows and two columns:
* a column x containing random floating point numbers,
* and a column y where each cell contains a Unicode string of 100
space-separated mostly-cyrillic words.
See the attached [^data.py]. When I saved that 500k-row table as parquet with
gzip compression, the resulting file was 174 MB.
I tried running Adam's test snippet (the code I used is attached as [^main.rs])
while compiling with different versions of parquet:
* parquet=0.15.1
* parquet=1.0.1
* parquet=2.0.0-SNAPSHOT (specifically git:3fae71b10c42 of 2020-09-30).
*In all three cases running the snippet took almost exactly 150 seconds,* give
or take one second.
Does that help you decide whether to close the question, [~nevi_me]? Or perhaps
your comment, Adam, from 2019-10-07 used some other version to get that speed
improvement? Should I change the test to use the ParquetFileArrowReader example
in
[https://github.com/apache/arrow/blob/3fae71b10c42/rust/parquet/src/arrow/mod.rs#L25-L50,]
and then this issue can close if that one is faster?
> [Rust] Reading parquet file is slow
> -----------------------------------
>
> Key: ARROW-6774
> URL: https://issues.apache.org/jira/browse/ARROW-6774
> Project: Apache Arrow
> Issue Type: Improvement
> Components: Rust
> Affects Versions: 0.15.0
> Reporter: Adam Lippai
> Priority: Major
> Attachments: data.py, main.rs
>
>
> Using the example at
> [https://github.com/apache/arrow/tree/master/rust/parquet] is slow.
> The snippet
> {code:none}
> let reader = SerializedFileReader::new(file).unwrap();
> let mut iter = reader.get_row_iter(None).unwrap();
> let start = Instant::now();
> while let Some(record) = iter.next() {}
> let duration = start.elapsed();
> println!("{:?}", duration);
> {code}
> Runs for 17sec for a ~160MB parquet file.
> If there is a more effective way to load a parquet file, it would be nice to
> add it to the readme.
> P.S.: My goal is to construct an ndarray from it, I'd be happy for any tips.
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