import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/**
 * 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());
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceNestedCaseWhen() {
  HepProgram preProgram = new HepProgramBuilder()
      .build();

  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  HepPlanner hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.FILTER_INSTANCE);

  final String sql = "select sal\n"
          + "from emp\n"
          + "where case when (sal = 1000) then\n"
          + "(case when sal = 1000 then null else 1 end is null) else\n"
          + "(case when sal = 2000 then null else 1 end is null) end is true";
  checkPlanning(tester, preProgram, hepPlanner, sql);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-1479">[CALCITE-1479]
 * AssertionError in ReduceExpressionsRule on multi-column IN
 * sub-query</a>. */
@Test public void testReduceCompositeInSubQuery() {
  final HepProgram hepProgram = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .build();
  final String sql = "select *\n"
      + "from emp\n"
      + "where (empno, deptno) in (\n"
      + "  select empno, deptno from (\n"
      + "    select empno, deptno\n"
      + "    from emp\n"
      + "    group by empno, deptno))\n"
      + "or deptno < 40 + 60";
  checkSubQuery(sql)
      .with(hepProgram)
      .check();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-571">[CALCITE-571]
 * ReduceExpressionsRule tries to reduce SemiJoin condition to non-equi
 * condition</a>. */
@Test public void testSemiJoinReduceConstants() {
  final HepProgram preProgram = HepProgram.builder()
      .addRuleInstance(SemiJoinRule.PROJECT)
      .build();
  final HepProgram program = HepProgram.builder()
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();
  final String sql = "select e1.sal\n"
      + "from (select * from emp where deptno = 200) as e1\n"
      + "where e1.deptno in (\n"
      + "  select e2.deptno from emp e2 where e2.sal = 100)";
  sql(sql)
      .withDecorrelation(false)
      .withTrim(true)
      .withPre(preProgram)
      .with(program)
      .checkUnchanged();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceConstants() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  // NOTE jvs 27-May-2006: among other things, this verifies
  // intentionally different treatment for identical coalesce expression
  // in select and where.

  // There is "CAST(2 AS INTEGER)" in the plan because 2 has type "INTEGER NOT
  // NULL" and we need "INTEGER".
  final String sql = "select"
      + " 1+2, d.deptno+(3+4), (5+6)+d.deptno, cast(null as integer),"
      + " coalesce(2,null), row(7+8)"
      + " from dept d inner join emp e"
      + " on d.deptno = e.deptno + (5-5)"
      + " where d.deptno=(7+8) and d.deptno=(8+7) and d.deptno=coalesce(2,null)";
  sql(sql).with(program)
      .withProperty(Hook.REL_BUILDER_SIMPLIFY, false)
      .check();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceConstantsCaseEquals2() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  // Equivalent to 'case when deptno = 20 then false
  //                     when deptno = 10 then true
  //                     else null end'
  checkPlanning(program,
      "select count(1) from emp\n"
          + "where case deptno\n"
          + "  when 20 then 2\n"
          + "  when 10 then 1\n"
          + "  else cast(null as integer) end = 1");
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceConstantsCaseEquals3() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  // Equivalent to 'deptno = 30 or deptno = 10'
  checkPlanning(program,
      "select count(1) from emp\n"
          + "where case deptno\n"
          + "  when 30 then 1\n"
          + "  when 20 then 2\n"
          + "  when 10 then 1\n"
          + "  when 30 then 111\n"
          + "  else 0 end = 1");
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Ignore // Calcite does not support INSERT yet
@Test public void testReduceCastsNullable() throws Exception {
  HepProgram program = new HepProgramBuilder()

      // Simulate the way INSERT will insert casts to the target types
      .addRuleInstance(
          new CoerceInputsRule(LogicalTableModify.class, false,
              RelFactories.LOGICAL_BUILDER))

          // Convert projects to calcs, merge two calcs, and then
          // reduce redundant casts in merged calc.
      .addRuleInstance(ProjectToCalcRule.INSTANCE)
      .addRuleInstance(CalcMergeRule.INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.CALC_INSTANCE)
      .build();
  checkPlanning(program,
      "insert into sales.depts(name) "
          + "select cast(gender as varchar(128)) from sales.emps");
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-2110">[CALCITE-2110]
 * ArrayIndexOutOfBoundsException in RexSimplify when using
 * ReduceExpressionsRule.JOIN_INSTANCE</a>. */
@Test public void testCorrelationScalarAggAndFilter() {
  final String sql = "SELECT e1.empno\n"
      + "FROM emp e1, dept d1 where e1.deptno = d1.deptno\n"
      + "and e1.deptno < 10 and d1.deptno < 15\n"
      + "and e1.sal > (select avg(sal) from emp e2 where e1.empno = e2.empno)";
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();
  sql(sql)
      .withDecorrelation(true)
      .withTrim(true)
      .expand(true)
      .withPre(program)
      .with(program)
      .checkUnchanged();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
public DrillSqlWorker(QueryContext context) {
  final List<RelTraitDef> traitDefs = new ArrayList<RelTraitDef>();

  traitDefs.add(ConventionTraitDef.INSTANCE);
  traitDefs.add(DrillDistributionTraitDef.INSTANCE);
  traitDefs.add(RelCollationTraitDef.INSTANCE);
  this.context = context;
  RelOptCostFactory costFactory = (context.getPlannerSettings().useDefaultCosting()) ?
      null : new DrillCostBase.DrillCostFactory() ;
  int idMaxLength = (int)context.getPlannerSettings().getIdentifierMaxLength();

  FrameworkConfig config = Frameworks.newConfigBuilder() //
      .parserConfig(SqlParser.configBuilder()
          .setLex(Lex.MYSQL)
          .setIdentifierMaxLength(idMaxLength)
          .setParserFactory(DrillParserWithCompoundIdConverter.FACTORY)
          .build()) //
      .defaultSchema(context.getNewDefaultSchema()) //
      .operatorTable(context.getDrillOperatorTable()) //
      .traitDefs(traitDefs) //
      .convertletTable(new DrillConvertletTable()) //
      .context(context.getPlannerSettings()) //
      .ruleSets(getRules(context)) //
      .costFactory(costFactory) //
      .executor(new DrillConstExecutor(context.getFunctionRegistry(), context, context.getPlannerSettings()))
      .typeSystem(DrillRelDataTypeSystem.DRILL_REL_DATATYPE_SYSTEM) //
      .build();
  this.planner = Frameworks.getPlanner(config);
  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  builder.addRuleClass(ProjectToWindowRule.class);
  this.hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.CALC_INSTANCE);
  hepPlanner.addRule(ProjectToWindowRule.PROJECT);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
private long checkRuleApplyCount(HepMatchOrder matchOrder) {
  final HepProgramBuilder programBuilder = HepProgram.builder();
  programBuilder.addMatchOrder(matchOrder);
  programBuilder.addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE);
  programBuilder.addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE);

  final HepTestListener listener = new HepTestListener(0);
  HepPlanner planner = new HepPlanner(programBuilder.build());
  planner.addListener(listener);
  planner.setRoot(tester.convertSqlToRel(COMPLEX_UNION_TREE).rel);
  planner.findBestExp();
  return listener.getApplyTimes();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceNot() {
  HepProgram preProgram = new HepProgramBuilder()
      .build();

  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  HepPlanner hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.FILTER_INSTANCE);

  final String sql = "select *\n"
      + "from (select (case when sal > 1000 then null else false end) as caseCol from emp)\n"
      + "where NOT(caseCol)";
  checkPlanning(tester, preProgram, hepPlanner, sql, true);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceOrCaseWhen() {
  HepProgram preProgram = new HepProgramBuilder()
      .build();

  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  HepPlanner hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.FILTER_INSTANCE);

  final String sql = "select sal\n"
      + "from emp\n"
      + "where case when sal = 1000 then null else 1 end is null\n"
      + "OR case when sal = 2000 then null else 1 end is null";
  checkPlanning(tester, preProgram, hepPlanner, sql);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceNullableCase() {
  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  HepPlanner hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.PROJECT_INSTANCE);

  final String sql = "SELECT CASE WHEN 1=2 "
      + "THEN cast((values(1)) as integer) "
      + "ELSE 2 end from (values(1))";
  sql(sql).with(hepPlanner).check();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceNullableCase2() {
  HepProgramBuilder builder = new HepProgramBuilder();
  builder.addRuleClass(ReduceExpressionsRule.class);
  HepPlanner hepPlanner = new HepPlanner(builder.build());
  hepPlanner.addRule(ReduceExpressionsRule.PROJECT_INSTANCE);

  final String sql = "SELECT deptno, ename, CASE WHEN 1=2 "
      + "THEN substring(ename, 1, cast(2 as int)) ELSE NULL end from emp"
      + " group by deptno, ename, case when 1=2 then substring(ename,1, cast(2 as int))  else null end";
  sql(sql).with(hepPlanner).check();
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-570">[CALCITE-570]
 * ReduceExpressionsRule throws "duplicate key" exception</a>. */
@Test public void testReduceConstantsDup() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  final String sql = "select d.deptno"
      + " from dept d"
      + " where d.deptno=7 and d.deptno=8";
  checkPlanning(new HepPlanner(program), sql);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-935">[CALCITE-935]
 * Improve how ReduceExpressionsRule handles duplicate constraints</a>. */
@Test public void testReduceConstantsDup2() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  final String sql = "select *\n"
      + "from emp\n"
      + "where deptno=7 and deptno=8\n"
      + "and empno = 10 and mgr is null and empno = 10";
  checkPlanning(program, sql);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testPullNull() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  final String sql = "select *\n"
      + "from emp\n"
      + "where deptno=7\n"
      + "and empno = 10 and mgr is null and empno = 10";
  checkPlanning(program, sql);
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
@Test public void testReduceConstants2() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  checkPlanning(program,
      "select p1 is not distinct from p0 from (values (2, cast(null as integer))) as t(p0, p1)");
}
 

import org.apache.calcite.rel.rules.ReduceExpressionsRule; //导入依赖的package包/类
/** Test case for
 * <a href="https://issues.apache.org/jira/browse/CALCITE-902">[CALCITE-902]
 * Match nullability when reducing expressions in a Project</a>. */
@Test public void testReduceConstantsProjectNullable() throws Exception {
  HepProgram program = new HepProgramBuilder()
      .addRuleInstance(ReduceExpressionsRule.PROJECT_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.FILTER_INSTANCE)
      .addRuleInstance(ReduceExpressionsRule.JOIN_INSTANCE)
      .build();

  checkPlanning(program, "select mgr from emp where mgr=10");
}