Arrow: Release vectors decoded from dictionary encoded columns - #17742
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chiragkava wants to merge 1 commit into
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Arrow: Release vectors decoded from dictionary encoded columns#17742chiragkava wants to merge 1 commit into
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| ColumnVector[] columnVectors = new ColumnVector[readers.length]; | ||
| // release the decoded vectors the previous batch materialized, safe with reused containers |
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Fixes #17722.
ColumnVector.getArrowVector()allocates a decoded vector per call for dictionary encoded columns and nothing released it (details in the issue). Following the ownership model of #17296, the decoded vector is now materialized once per batch andArrowBatchReaderreleases it when the nextread()invalidates the batch and onclose(). Only dict-decoded vectors are released, soreuseContainersand the reader-owned holder vectors are untouched.Spark/Flink don't use this code path.
Tested with a differential pair in
TestArrowReader: the materializing test fails on main (33,280 bytes retained for 100 rows / 1 batch / 1 string column) and passes with the fix. the non-materializing control passes on both.This contribution was developed with AI assistance Claude Code (Opus 5) and I have reviewed it