saffron.sql
Class AddFilterToQueryRule

java.lang.Object
  |
  +--saffron.opt.Rule
        |
        +--saffron.sql.AddFilterToQueryRule

class AddFilterToQueryRule

extends Rule

AddFilterToQueryRule grafts a Filter onto a JdbcQuery.

This rule only works if the query's select clause is "*". If you start with a Filter on a Project on a JavaTableAccess, this will not be the case. You can fix it by pushing the filter through the project. (todo: Implement a rule to do this.)

Field Summary

Fields inherited from class saffron.opt.Rule

description, planner

Constructor Summary

(package private)

AddFilterToQueryRule()

Method Summary

void	onMatch(RuleCall call) This method is called every time the rule matches.

Methods inherited from class saffron.opt.Rule

convert, getOutConvention, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AddFilterToQueryRule

AddFilterToQueryRule()

Method Detail

onMatch

public void onMatch(RuleCall call)

Description copied from class: Rule

This method is called every time the rule matches. 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 RuleCall.transformTo(saffron.rel.Rel) to register the expression.

Specified by:

onMatch in class Rule