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Fix a bug with min/max aggregation. #277
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LGTM. |
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This PR fixes the bug with min/max aggregation (that produces incorrect results) when the aggregated column is stored with leading-zero-truncation compression.
The bug happens because the untyped value (i.e. a
const void *pointer) obtained from the leading-zero-truncation compressed column's correspondingValueAccessoris the address of a temporary buffer -- i.e. the value pointer becomes invalid when the nextaccessor->next()gets called. Keeping the value pointer across multiple iterations of accessor->next() causes the problem.The fix is to copy the value pointer's underlying value to a local variable (so that the value remains valid across iterations of accessor->next()).