anjakefala opened a new pull request, #40565: URL: https://github.com/apache/arrow/pull/40565
### Rationale for this change Mimalloc and jemalloc can allocate a [relatively large amount of memory for the ScalarMemoTable](https://github.com/apache/arrow/issues/40301). For this reason, the ScalarMemoTable should only be allocated when it is used (when `options.deduplicate_objects=True`). I tested this change, and for small tables it does improve memory allocation. `options.deduplicate_objects=False` After this change: 📦 Total memory allocated: 174.422MB 📊 Histogram of allocation size: min: 1.000B -------------------------------------------- < 6.000B : 3064 ▇▇ < 36.000B : 7533 ▇▇▇▇ < 222.000B : 9974 ▇▇▇▇▇ < 1.319KB : 53264 ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ < 7.999KB : 5188 ▇▇▇ < 48.503KB : 742 ▇ < 294.066KB: 102 ▇ < 1.741MB : 22 ▇ < 10.556MB : 1 ▇ <=64.000MB : 1 ▇ -------------------------------------------- max: 64.000MB Before this change: 📦 Total memory allocated: 1.295GB 📊 Histogram of allocation size: min: 1.000B -------------------------------------------- < 6.000B : 3064 ▇▇ < 36.000B : 7543 ▇▇▇▇ < 222.000B : 10009 ▇▇▇▇▇ < 1.319KB : 53269 ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ < 7.999KB : 5192 ▇▇▇ < 48.503KB : 761 ▇ < 294.066KB: 102 ▇ < 1.741MB : 22 ▇ < 10.556MB : 1 ▇ <=64.000MB : 19 ▇ -------------------------------------------- max: 64.000MB ### What changes are included in this PR? The allocation of `memo_table` and `unique_values` have been moved underneath an `if (options.deduplicate_objects)` block. Since they are used within a lambda, they have been changed to shared pointers, so that their values exist for the lifetime needed. ### Are these changes tested? `deduplicate_objects` has extensive existing tests: https://github.com/apache/arrow/blob/b235f83ed10bcad174b267113479a24ca045def5/python/pyarrow/tests/test_pandas.py#L3211 and https://github.com/apache/arrow/blob/b235f83ed10bcad174b267113479a24ca045def5/python/benchmarks/convert_pandas.py#L71 ### Are there any user-facing changes? Nope. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
