Interface IQueryMetaContext
- All Known Implementing Classes:
AbstractQueryMetaContext
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Method Summary
Modifier and TypeMethodDescriptionboolean
Tells whether the givenIInputKey
is an edge and may lead out of scope.getConditionalImplications
(IInputKey implyingKey) Returns known "double dispatch" implications, where the given implying key implies other input keys under certain additional conditions (themselves input keys).Returns functional dependencies of the input key expressed in terms of column indices.getImplications
(IInputKey implyingKey) Returns known direct implications, e.g.getPosetComparator
(Iterable<IInputKey> keys) Returns anIPosetComparator
for the given set ofIInputKey
s.For query normalizing, this is the order suggested for trying to eliminate input keys.getWeakenedAlternatives
(IInputKey implyingKey) Returns a set of implications (weakened alternatives), with a suggestion for the query planner that satisfying them first may help in satisfying the implying key.boolean
isEnumerable
(IInputKey key) Returns true iff instance tuples of the given key can be enumerated.boolean
isPosetKey
(IInputKey key) Returns true if the givenIInputKey
represents a poset type.boolean
isStateless
(IInputKey key) Returns true iff the set of instance tuples of the given key is immutable.
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Method Details
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isEnumerable
Returns true iff instance tuples of the given key can be enumerated.If false, the runtime can only test tuple membership in the extensional relation identified by the key, but not enumerate member tuples in general.
Equivalent to
IInputKey.isEnumerable()
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isStateless
Returns true iff the set of instance tuples of the given key is immutable.If false, the runtime provides notifications upon change.
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getWeakenedAlternatives
Returns a set of implications (weakened alternatives), with a suggestion for the query planner that satisfying them first may help in satisfying the implying key.Note that for the obvious reasons, enumerable keys can only be implied by enumerable keys.
Must follow directly or transitively from implications of
getImplications(IInputKey)
.- Since:
- 1.6
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getImplications
Returns known direct implications, e.g. edge supertypes, edge opposites, node type constraints, etc.Note that for the obvious reasons, enumerable keys can only be implied by enumerable keys.
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getConditionalImplications
Returns known "double dispatch" implications, where the given implying key implies other input keys under certain additional conditions (themselves input keys). For example, a "type x, unscoped" input key may imply the "type x, in scope" input key under the condition of the input key "x is in scope"Note that for the obvious reasons, enumerable keys can only be implied by enumerable keys (either as the implying key or as the additional condition).
Note that symmetry is not required, i.e. the additional conditions do not have to list the same conditional implication.
- Returns:
- multi-map, where the keys are additional conditions and the values are input key implications jointly implied by the condition and the given implying key.
- Since:
- 2.0
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getFunctionalDependencies
Returns functional dependencies of the input key expressed in terms of column indices.Each entry of the map is a functional dependency rule, where the entry key specifies source columns and the entry value specifies target columns.
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getSuggestedEliminationOrdering
Comparator<IInputKey> getSuggestedEliminationOrdering()For query normalizing, this is the order suggested for trying to eliminate input keys.- Since:
- 1.6
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canLeadOutOfScope
Tells whether the givenIInputKey
is an edge and may lead out of scope.- Since:
- 1.6
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isPosetKey
Returns true if the givenIInputKey
represents a poset type.- Since:
- 1.6
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getPosetComparator
Returns anIPosetComparator
for the given set ofIInputKey
s.- Parameters:
keys
- an iterable collection of input keys- Returns:
- the poset comparator
- Since:
- 1.6
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