branch-3.1:[enhancement](parquet)Optimize the performance of parquet reader when decode RLE_DICTIONARY encoding (#57208)#57614
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morningman merged 1 commit intoapache:branch-3.1from Nov 4, 2025
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… decode RLE_DICTIONARY encoding (apache#57208) Problem Summary: When parsing RLE_DICTIONARY encoding, the parquet reader uniformly uses memcpy. However, for INT32, INT64, etc., direct assignment is faster than memcpy. In Parquet dictionary encoding, the actual data is not stored contiguously, resulting in very small memcpy sizes. When analyzing the implementation of `memcpy`, we can see that for such small sizes, `__builtin_memcpy` is used instead. The implementation of `__builtin_memcpy` essentially behaves like a series of simple assignments. You can observe the corresponding assembly code here: https://godbolt.org/z/r9Ma1ozvd.
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morrySnow
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Nov 4, 2025
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bp #57208
Problem Summary:
When parsing RLE_DICTIONARY encoding, the parquet reader uniformly uses memcpy. However, for INT32, INT64, etc., direct assignment is faster than memcpy.
In Parquet dictionary encoding, the actual data is not stored contiguously, resulting in very small memcpy sizes. When analyzing the implementation of
memcpy, we can see that for such small sizes,__builtin_memcpyis used instead. The implementation of__builtin_memcpyessentially behaves like a series of simple assignments. You can observe the corresponding assembly code here: https://godbolt.org/z/r9Ma1ozvd.What problem does this PR solve?
Issue Number: close #xxx
Related PR: #xxx
Problem Summary:
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