improve performance of the main-table path check during feature decoding#557
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NestingTracker.isNotMain() is called for every value row while decoding and did a List<List<String>>.contains(path), i.e. a linear scan with element-wise list equality. Make the main-table paths a Set so the membership test is O(1), and build it as a Set at the source in FeatureDecoderSql (the only caller). The main table path repeats once per sub-query, so the Set also drops the many duplicates the List carried. Membership semantics are unchanged, so the decoded output is identical.
azahnen
approved these changes
Jul 10, 2026
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NestingTracker.isNotMain()is called for every value row while decoding and did aList<List<String>>.contains(path), i.e. a linear scan with element-wise list equality. Make the main-table paths a Set so the membership test is O(1), and build it as a Set at the source in FeatureDecoderSql (the only caller). The main table path repeats once per sub-query, so the Set also drops the many duplicates the List carried. Membership semantics are unchanged, so the decoded output is identical.