Class PushProjectPastSetOpRule

  extended by org.eigenbase.relopt.RelOptRule
      extended by org.eigenbase.rel.rules.PushProjectPastSetOpRule

public class PushProjectPastSetOpRule
extends RelOptRule

PushProjectPastSetOpRule implements the rule for pushing a ProjectRel past a SetOpRel. The children of the SetOpRel will project only the RexInputRefs referenced in the original ProjectRel.

$Id: //open/dev/farrago/src/org/eigenbase/rel/rules/ $
Zelaine Fong

Field Summary
static PushProjectPastSetOpRule instance
private  PushProjector.ExprCondition preserveExprCondition
          Expressions that should be preserved in the projection
Fields inherited from class org.eigenbase.relopt.RelOptRule
ANY, description, operands
Constructor Summary
private PushProjectPastSetOpRule()
          Creates a PushProjectPastSetOpRule.
  PushProjectPastSetOpRule(PushProjector.ExprCondition preserveExprCondition)
          Creates a PushProjectPastSetOpRule with an explicit condition whether to preserve expressions.
Method Summary
 void onMatch(RelOptRuleCall call)
          Receives notification about a rule match.
Methods inherited from class org.eigenbase.relopt.RelOptRule
convert, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, mergeTraitsAndConvert, mergeTraitsAndConvert, toString
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail


public static final PushProjectPastSetOpRule instance


private PushProjector.ExprCondition preserveExprCondition
Expressions that should be preserved in the projection

Constructor Detail


private PushProjectPastSetOpRule()
Creates a PushProjectPastSetOpRule.


public PushProjectPastSetOpRule(PushProjector.ExprCondition preserveExprCondition)
Creates a PushProjectPastSetOpRule with an explicit condition whether to preserve expressions.

preserveExprCondition - Condition whether to preserve expressions
Method Detail


public void onMatch(RelOptRuleCall call)
Description copied from class: RelOptRule
Receives notification about a rule match. At the time that this method is called, 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.eigenbase.rel.RelNode) to register the expression.

Specified by:
onMatch in class RelOptRule
call - Rule call
See Also: