Hi all, I found a memory leak in plpython3u. It happens when converting the argument for an spi plan execution (via plpy.execute() or similar). I've attached a sql file to create two plpython3u functions to reproduce the issue (memory_leak_test.sql).
When running ``` set client_min_messages = 'debug'; select test_mem(1000); ``` You'll see that the memory goes to 720MB. In contrast the test_mem_query function you won't see the leak (it uses ~70MB): ``` set client_min_messages = 'debug'; select test_mem_query(1000); ``` This is because test_mem_query executes the query using a sql string instead of a spi plan with parameters. I believe the issue is in the call to `PLy_output_convert` inside `PLy_spi_execute_plan`. I've attached a patch that reduces the memory usage to ~70MB from ~720 MB when using test_mem. I based what I did on what `PLy_input_convert` does. But I am not an expert in this part of the code so I am not sure the patch is correct. In particular, I don't fully grasp the comment in `PLy_input_convert` about why the scratch is reset before not after the conversion cycle and what that has to do with python refcounts. A review by an expert would be appreciated. Thanks, Mat -- Mat Arye, Technical lead of all thing AI @ Timescale
memory_leak_test.sql
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memory_leak.patch
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