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Julian Hyde commented on CALCITE-3963: -------------------------------------- I don't understand what you mean by 'associative property in RelSet'. I don't think that your algorithm - to use 'The first RelNode added to the set or the RelNode with highest confidence level of estimated statistics.' - is sound. As I have explained earlier, 'highest confidence' does not have a satisfactory definition. Nor does 'first RelNode added to the set', in the case of sets merging or other perturbations of planning order. > Maintain logical properties at RelSet (equivalent group) instead of RelNode > --------------------------------------------------------------------------- > > Key: CALCITE-3963 > URL: https://issues.apache.org/jira/browse/CALCITE-3963 > Project: Calcite > Issue Type: Bug > Reporter: Xiening Dai > Assignee: Xiening Dai > Priority: Major > Time Spent: 40m > Remaining Estimate: 0h > > Currently the logical properties (such as row count, distinct row count, etc) > are maintained at RelNode level. This creates a number of meta data > consistency problems, e.g. CALCITE-1048, CALCITE-2166. > In theory, all RelNodes in a RelSet should share the same logical properties > per definition of relational equivalence. So it makes more sense to keep > logical properties at RelSet level, rather than the RelNode. And such > properties shouldn't change when new sub set is created or subset's best is > changed. > Specifically I think below build in metadata should fall into the logical > properties category - > Selectivity > UniqueKeys > ColumnUniqueness > RowCount > MaxRowCount > MinRowCount > DistinctRowCount > Size (averageRowSize, averageColumnSize) > > > > -- This message was sent by Atlassian Jira (v8.3.4#803005)