[ 
https://issues.apache.org/jira/browse/ARROW-6910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16968675#comment-16968675
 ] 

V Luong commented on ARROW-6910:
--------------------------------

ok [~wesm] let me create a new JIRA ticket for 0.15.1

> [Python] pyarrow.parquet.read_table(...) takes up lots of memory which is not 
> released until program exits
> ----------------------------------------------------------------------------------------------------------
>
>                 Key: ARROW-6910
>                 URL: https://issues.apache.org/jira/browse/ARROW-6910
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: C++, Python
>    Affects Versions: 0.15.0
>            Reporter: V Luong
>            Assignee: Wes McKinney
>            Priority: Critical
>              Labels: pull-request-available
>             Fix For: 1.0.0, 0.15.1
>
>         Attachments: arrow6910.png
>
>          Time Spent: 4h 50m
>  Remaining Estimate: 0h
>
> I realize that when I read up a lot of Parquet files using 
> pyarrow.parquet.read_table(...), my program's memory usage becomes very 
> bloated, although I don't keep the table objects after converting them to 
> Pandas DFs.
> You can try this in an interactive Python shell to reproduce this problem:
> ```{python}
> from tqdm import tqdm
> from pyarrow.parquet import read_table
> PATH = '/tmp/big.snappy.parquet'
> for _ in tqdm(range(10)):
>     read_table(PATH, use_threads=False, memory_map=False)
>     (note that I'm not assigning the read_table(...) result to anything, so 
> I'm not creating any new objects at all)
> ```
> During the For loop above, if you view the memory usage (e.g. using htop 
> program), you'll see that it keeps creeping up. Either the program crashes 
> during the 10 iterations, or if the 10 iterations complete, the program will 
> still occupy a huge amount of memory, although no objects are kept. That 
> memory is only released when you exit() from Python.
> This problem means that my compute jobs using PyArrow currently need to use 
> bigger server instances than I think is necessary, which translates to 
> significant extra cost.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to