Fix colNDVBySeg attnum index mismatch in column-specific ANALYZE #1680
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yjhjstz wants to merge 2 commits intoapache:mainfrom
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Fix colNDVBySeg attnum index mismatch in column-specific ANALYZE #1680yjhjstz wants to merge 2 commits intoapache:mainfrom
yjhjstz wants to merge 2 commits intoapache:mainfrom
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When ANALYZE is run on specific columns (e.g., ANALYZE t (col)) or when a table has dropped columns, the vacattrstats loop index `i` diverges from the attribute's actual attnum-1 index used by colNDVBySeg. Two fixes: 1. QD side (line 887): read colNDVBySeg[attnum-1] instead of colNDVBySeg[i] when storing stadistinctbyseg. 2. Segment side (line 1011): write ctx->stadistincts[attnum-1] instead of ctx->stadistincts[i] when collecting per-segment NDV.
ANALYZE t(b) puts column b at loop index i=0 on the QD, but b has attnum=2, so attnum-1=1 != i=0. The fix in do_analyze_rel (using attnum-1 instead of i to index colNDVBySeg) ensures stadistinctbyseg is read from the correct per-segment NDV slot. Test verifies stadistinctbyseg for column b equals 100 (all distinct) rather than ~5 (NDV of column a at index 0).
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Fixes #ISSUE_Number
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