DrillRuleSets.java 文件源码

/**
 * Get a list of logical rules that can be turned on or off by session/system options.
 *
 * If a rule is intended to always be included with the logical set, it should be added
 * to the immutable list created in the getDrillBasicRules() method below.
 *
 * @param optimizerRulesContext - used to get the list of planner settings, other rules may
 *                                also in the future need to get other query state from this,
 *                                such as the available list of UDFs (as is used by the
 *                                DrillMergeProjectRule created in getDrillBasicRules())
 * @return - a list of rules that have been filtered to leave out
 *         rules that have been turned off by system or session settings
 */
public static RuleSet getDrillUserConfigurableLogicalRules(OptimizerRulesContext optimizerRulesContext) {
  final PlannerSettings ps = optimizerRulesContext.getPlannerSettings();

  // This list is used to store rules that can be turned on an off
  // by user facing planning options
  final Builder<RelOptRule> userConfigurableRules = ImmutableSet.<RelOptRule>builder();

  if (ps.isConstantFoldingEnabled()) {
    // TODO - DRILL-2218
    userConfigurableRules.add(ReduceExpressionsRule.PROJECT_INSTANCE);

    userConfigurableRules.add(DrillReduceExpressionsRule.FILTER_INSTANCE_DRILL);
    userConfigurableRules.add(DrillReduceExpressionsRule.CALC_INSTANCE_DRILL);
  }

  return new DrillRuleSet(userConfigurableRules.build());
}