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https://issues.apache.org/jira/browse/CALCITE-7757?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Darpan Lunagariya (e6data) updated CALCITE-7757:
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Description:
h2. Summary
{{RelMdFunctionalDependency}} currently infers functional dependencies that do
not always hold under SQL null, grouping, ordinal, and value-equality semantics.
{{AggregateRemoveDuplicateKeysRule}} consumes this metadata and can
consequently remove a necessary grouping key, changing query results.
h2. Correctness problems
# *Outer-join equality dependencies* - {{LEFT}} and {{RIGHT}} joins must not
infer bidirectional functional dependencies from equality predicates when null
generation invalidates one direction.
# *Dependencies from null-generated inputs* - Outer joins must not blindly
preserve functional dependencies from the null-generated input because null
padding can invalidate them.
# *Incorrect Aggregate ordinal mapping* - Aggregate input group ordinals must
be mapped to packed output positions before exposing their functional
dependencies.
# *Equality-derived dependencies for approximate numerics* - Equality
predicates involving {{FLOAT}} or {{DOUBLE}} must not produce functional
dependencies when SQL equality and grouping equality differ.
# *Unsafe derived-expression dependencies* - Determinism alone is insufficient
for removing derived grouping expressions; unsafe scalar and nested types must
be rejected.
# *Grouping-set aggregate dependencies* - Grouping columns must not be assumed
to determine aggregate results when grouping sets can produce identical
null-padded keys.
# *Projected TableScan ordinals* - Table keys expressed in base-table ordinals
must not be applied directly to projected or reordered {{TableScan}} output
columns.
# *Unsafe generic unary-node passthrough* - Unknown single-input relational
nodes must not automatically inherit input functional dependencies because they
may change schema, values, or cardinality.
# *Join offsets with system fields* - Functional-dependency ordinals for join
inputs must account for system fields prefixed to the output, including semi
and anti joins.
# *Equality-derived dependencies for collated values* - Equality using a custom
collator can consider strings equal even when Enumerable grouping distinguishes
their Java keys, making the inferred dependency unsafe.
was:
h2. Summary
{{RelMdFunctionalDependency}} currently infers functional dependencies that do
not always hold under SQL null, grouping, ordinal, and value-equality semantics.
{{AggregateRemoveDuplicateKeysRule}} consumes this metadata and can
consequently remove a necessary grouping key, changing query results.
h2. Correctness problems
# *Outer-join equality dependencies* — {{LEFT}} and {{RIGHT}} joins must not
infer bidirectional functional dependencies from equality predicates when null
generation invalidates one direction.
# *Dependencies from null-generated inputs* — Outer joins must not blindly
preserve functional dependencies from the null-generated input because null
padding can invalidate them.
# *Incorrect Aggregate ordinal mapping* — Aggregate input group ordinals must
be mapped to packed output positions before exposing their functional
dependencies.
# *Equality-derived dependencies for approximate numerics* — Equality
predicates involving {{FLOAT}} or {{DOUBLE}} must not produce functional
dependencies when SQL equality and grouping equality differ.
# *Unsafe derived-expression dependencies* — Determinism alone is insufficient
for removing derived grouping expressions; unsafe scalar and nested types must
be rejected.
# *Grouping-set aggregate dependencies* — Grouping columns must not be assumed
to determine aggregate results when grouping sets can produce identical
null-padded keys.
# *Projected TableScan ordinals* — Table keys expressed in base-table ordinals
must not be applied directly to projected or reordered {{TableScan}} output
columns.
# *Unsafe generic unary-node passthrough* — Unknown single-input relational
nodes must not automatically inherit input functional dependencies because they
may change schema, values, or cardinality.
# *Join offsets with system fields* — Functional-dependency ordinals for join
inputs must account for system fields prefixed to the output, including semi
and anti joins.
# *Equality-derived dependencies for collated values* — Equality using a custom
collator can consider strings equal even when Enumerable grouping distinguishes
their Java keys, making the inferred dependency unsafe.
> RelMdFunctionalDependency can infer unsound dependencies and cause incorrect
> query results
> ------------------------------------------------------------------------------------------
>
> Key: CALCITE-7757
> URL: https://issues.apache.org/jira/browse/CALCITE-7757
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.42.0
> Reporter: Darpan Lunagariya (e6data)
> Assignee: Darpan Lunagariya (e6data)
> Priority: Major
> Labels: pull-request-available
>
> h2. Summary
> {{RelMdFunctionalDependency}} currently infers functional dependencies that
> do not always hold under SQL null, grouping, ordinal, and value-equality
> semantics.
> {{AggregateRemoveDuplicateKeysRule}} consumes this metadata and can
> consequently remove a necessary grouping key, changing query results.
> h2. Correctness problems
> # *Outer-join equality dependencies* - {{LEFT}} and {{RIGHT}} joins must not
> infer bidirectional functional dependencies from equality predicates when
> null generation invalidates one direction.
> # *Dependencies from null-generated inputs* - Outer joins must not blindly
> preserve functional dependencies from the null-generated input because null
> padding can invalidate them.
> # *Incorrect Aggregate ordinal mapping* - Aggregate input group ordinals must
> be mapped to packed output positions before exposing their functional
> dependencies.
> # *Equality-derived dependencies for approximate numerics* - Equality
> predicates involving {{FLOAT}} or {{DOUBLE}} must not produce functional
> dependencies when SQL equality and grouping equality differ.
> # *Unsafe derived-expression dependencies* - Determinism alone is
> insufficient for removing derived grouping expressions; unsafe scalar and
> nested types must be rejected.
> # *Grouping-set aggregate dependencies* - Grouping columns must not be
> assumed to determine aggregate results when grouping sets can produce
> identical null-padded keys.
> # *Projected TableScan ordinals* - Table keys expressed in base-table
> ordinals must not be applied directly to projected or reordered {{TableScan}}
> output columns.
> # *Unsafe generic unary-node passthrough* - Unknown single-input relational
> nodes must not automatically inherit input functional dependencies because
> they may change schema, values, or cardinality.
> # *Join offsets with system fields* - Functional-dependency ordinals for join
> inputs must account for system fields prefixed to the output, including semi
> and anti joins.
> # *Equality-derived dependencies for collated values* - Equality using a
> custom collator can consider strings equal even when Enumerable grouping
> distinguishes their Java keys, making the inferred dependency unsafe.
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