public class IntersectToDistinctRule extends RelOptRule
Intersect
(all
= false
)
into a group of operators composed of
Union
,
Aggregate
, etc.
Rewrite: (GB-Union All-GB)-GB-UDTF (on all attributes)
Query: R1 Intersect All R2
R3 = GB(R1 on all attributes, count(*) as c)
union all
GB(R2 on all attributes, count(*) as c)
R4 = GB(R3 on all attributes, count(c) as cnt, min(c) as m)
Note that we do not need min(c)
in intersect distinct.
R5 = Filter(cnt == #branch)
If it is intersect all then
R6 = UDTF (R5) which will explode the tuples based on min(c)
R7 = Project(R6 on all attributes)
Else
R6 = Proj(R5 on all attributes)
UnionToDistinctRule
Modifier and Type | Field and Description |
---|---|
static IntersectToDistinctRule |
INSTANCE |
description, operands, relBuilderFactory
Constructor and Description |
---|
IntersectToDistinctRule(java.lang.Class<? extends Intersect> intersectClazz,
RelBuilderFactory relBuilderFactory)
Creates an IntersectToDistinctRule.
|
Modifier and Type | Method and Description |
---|---|
void |
onMatch(RelOptRuleCall call)
Receives notification about a rule match.
|
any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered
public static final IntersectToDistinctRule INSTANCE
public IntersectToDistinctRule(java.lang.Class<? extends Intersect> intersectClazz, RelBuilderFactory relBuilderFactory)
public void onMatch(RelOptRuleCall call)
RelOptRule
call.rels
holds the set of relational
expressions which match the operands to the rule;
call.rels[0]
is the root expression.
Typically a rule would check that the nodes are valid matches, creates
a new expression, then calls back RelOptRuleCall.transformTo(org.apache.calcite.rel.RelNode, java.util.Map<org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode>)
to
register the expression.
onMatch
in class RelOptRule
call
- Rule callRelOptRule.matches(RelOptRuleCall)
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