public boolean matches(RelOptRuleCall call) {
JoinRel join = (JoinRel) call.rels[0];
switch (join.getJoinType()) {
case INNER:
case LEFT:
return true;
case FULL:
case RIGHT:
return false;
default:
throw Util.unexpected(join.getJoinType());
}
}
/**
* Combines the join filters from the left and right inputs (if they are MultiJoinRels) with the
* join filter in the joinrel into a single AND'd join filter, unless the inputs correspond to
* null generating inputs in an outer join
*
* @param joinRel join rel
* @param left left child of the joinrel
* @param right right child of the joinrel
* @return combined join filters AND'd together
*/
private RexNode combineJoinFilters(JoinRel joinRel, RelNode left, RelNode right) {
RexBuilder rexBuilder = joinRel.getCluster().getRexBuilder();
JoinRelType joinType = joinRel.getJoinType();
// first need to adjust the RexInputs of the right child, since
// those need to shift over to the right
RexNode rightFilter = null;
if (canCombine(right, joinType.generatesNullsOnRight())) {
MultiJoinRel multiJoin = (MultiJoinRel) right;
rightFilter = shiftRightFilter(joinRel, left, multiJoin, multiJoin.getJoinFilter());
}
// AND the join condition if this isn't a left or right outer join;
// in those cases, the outer join condition is already tracked
// separately
RexNode newFilter = null;
if ((joinType != JoinRelType.LEFT) && (joinType != JoinRelType.RIGHT)) {
newFilter = joinRel.getCondition();
}
if (canCombine(left, joinType.generatesNullsOnLeft())) {
RexNode leftFilter = ((MultiJoinRel) left).getJoinFilter();
newFilter = RelOptUtil.andJoinFilters(rexBuilder, newFilter, leftFilter);
}
newFilter = RelOptUtil.andJoinFilters(rexBuilder, newFilter, rightFilter);
return newFilter;
}
/**
* Combines the outer join conditions and join types from the left and right join inputs. If the
* join itself is either a left or right outer join, then the join condition corresponding to the
* join is also set in the position corresponding to the null-generating input into the join. The
* join type is also set.
*
* @param joinRel join rel
* @param combinedInputs the combined inputs to the join
* @param left left child of the joinrel
* @param right right child of the joinrel
* @param combinedConds the array containing the combined join conditions
* @param joinTypes the array containing the combined join types
* @return combined join filters AND'd together
*/
private RexNode[] combineOuterJoins(
JoinRel joinRel,
RelNode[] combinedInputs,
RelNode left,
RelNode right,
RexNode[] combinedConds,
JoinRelType[] joinTypes) {
JoinRelType joinType = joinRel.getJoinType();
int nCombinedInputs = combinedInputs.length;
boolean leftCombined = canCombine(left, joinType.generatesNullsOnLeft());
boolean rightCombined = canCombine(right, joinType.generatesNullsOnRight());
if (joinType == JoinRelType.LEFT) {
if (leftCombined) {
copyOuterJoinInfo((MultiJoinRel) left, combinedConds, joinTypes, 0, 0, null, null);
} else {
joinTypes[0] = JoinRelType.INNER;
}
combinedConds[nCombinedInputs - 1] = joinRel.getCondition();
joinTypes[nCombinedInputs - 1] = joinType;
} else if (joinType == JoinRelType.RIGHT) {
if (rightCombined) {
copyOuterJoinInfo(
(MultiJoinRel) right,
combinedConds,
joinTypes,
1,
left.getRowType().getFieldCount(),
right.getRowType().getFields(),
joinRel.getRowType().getFields());
} else {
joinTypes[nCombinedInputs - 1] = JoinRelType.INNER;
}
combinedConds[0] = joinRel.getCondition();
joinTypes[0] = joinType;
} else {
int nInputsLeft;
if (leftCombined) {
nInputsLeft = left.getInputs().length;
copyOuterJoinInfo((MultiJoinRel) left, combinedConds, joinTypes, 0, 0, null, null);
} else {
nInputsLeft = 1;
joinTypes[0] = JoinRelType.INNER;
}
if (rightCombined) {
copyOuterJoinInfo(
(MultiJoinRel) right,
combinedConds,
joinTypes,
nInputsLeft,
left.getRowType().getFieldCount(),
right.getRowType().getFields(),
joinRel.getRowType().getFields());
} else {
joinTypes[nInputsLeft] = JoinRelType.INNER;
}
}
return combinedConds;
}
/**
* Combines the inputs into a JoinRel into an array of inputs.
*
* @param join original join
* @param left left input into join
* @param right right input into join
* @param projFieldsList returns a list of the new combined projection fields
* @param joinFieldRefCountsList returns a list of the new combined join field reference counts
* @return combined left and right inputs in an array
*/
private RelNode[] combineInputs(
JoinRel join,
RelNode left,
RelNode right,
List<BitSet> projFieldsList,
List<int[]> joinFieldRefCountsList) {
// leave the null generating sides of an outer join intact; don't
// pull up those children inputs into the array we're constructing
int nInputs;
int nInputsOnLeft;
MultiJoinRel leftMultiJoin = null;
JoinRelType joinType = join.getJoinType();
boolean combineLeft = canCombine(left, joinType.generatesNullsOnLeft());
if (combineLeft) {
leftMultiJoin = (MultiJoinRel) left;
nInputs = left.getInputs().length;
nInputsOnLeft = nInputs;
} else {
nInputs = 1;
nInputsOnLeft = 1;
}
MultiJoinRel rightMultiJoin = null;
boolean combineRight = canCombine(right, joinType.generatesNullsOnRight());
if (combineRight) {
rightMultiJoin = (MultiJoinRel) right;
nInputs += right.getInputs().length;
} else {
nInputs += 1;
}
RelNode[] newInputs = new RelNode[nInputs];
int i = 0;
if (combineLeft) {
for (; i < left.getInputs().length; i++) {
newInputs[i] = leftMultiJoin.getInput(i);
projFieldsList.add(((MultiJoinRel) left).getProjFields()[i]);
joinFieldRefCountsList.add(((MultiJoinRel) left).getJoinFieldRefCountsMap().get(i));
}
} else {
newInputs[0] = left;
i = 1;
projFieldsList.add(null);
joinFieldRefCountsList.add(new int[left.getRowType().getFieldCount()]);
}
if (combineRight) {
for (; i < nInputs; i++) {
newInputs[i] = rightMultiJoin.getInput(i - nInputsOnLeft);
projFieldsList.add(((MultiJoinRel) right).getProjFields()[i - nInputsOnLeft]);
joinFieldRefCountsList.add(
((MultiJoinRel) right).getJoinFieldRefCountsMap().get(i - nInputsOnLeft));
}
} else {
newInputs[i] = right;
projFieldsList.add(null);
joinFieldRefCountsList.add(new int[right.getRowType().getFieldCount()]);
}
return newInputs;
}
public void onMatch(RelOptRuleCall call) {
JoinRel origJoinRel = (JoinRel) call.rels[0];
RelNode left = call.rels[1];
RelNode right = call.rels[2];
// combine the children MultiJoinRel inputs into an array of inputs
// for the new MultiJoinRel
List<BitSet> projFieldsList = new ArrayList<BitSet>();
List<int[]> joinFieldRefCountsList = new ArrayList<int[]>();
RelNode[] newInputs =
combineInputs(origJoinRel, left, right, projFieldsList, joinFieldRefCountsList);
// combine the outer join information from the left and right
// inputs, and include the outer join information from the current
// join, if it's a left/right outer join
RexNode[] newOuterJoinConds = new RexNode[newInputs.length];
JoinRelType[] joinTypes = new JoinRelType[newInputs.length];
combineOuterJoins(origJoinRel, newInputs, left, right, newOuterJoinConds, joinTypes);
// pull up the join filters from the children MultiJoinRels and
// combine them with the join filter associated with this JoinRel to
// form the join filter for the new MultiJoinRel
RexNode newJoinFilter = combineJoinFilters(origJoinRel, left, right);
// add on the join field reference counts for the join condition
// associated with this JoinRel
Map<Integer, int[]> newJoinFieldRefCountsMap = new HashMap<Integer, int[]>();
addOnJoinFieldRefCounts(
newInputs,
origJoinRel.getRowType().getFieldCount(),
origJoinRel.getCondition(),
joinFieldRefCountsList,
newJoinFieldRefCountsMap);
RexNode newPostJoinFilter = combinePostJoinFilters(origJoinRel, left, right);
RelNode multiJoin =
new MultiJoinRel(
origJoinRel.getCluster(),
newInputs,
newJoinFilter,
origJoinRel.getRowType(),
(origJoinRel.getJoinType() == JoinRelType.FULL),
newOuterJoinConds,
joinTypes,
projFieldsList.toArray(new BitSet[projFieldsList.size()]),
newJoinFieldRefCountsMap,
newPostJoinFilter);
call.transformTo(multiJoin);
}
// implement RelOptRule
public void onMatch(RelOptRuleCall call) {
ProjectRel origProj = call.rel(0);
JoinRel joinRel = call.rel(1);
// locate all fields referenced in the projection and join condition;
// determine which inputs are referenced in the projection and
// join condition; if all fields are being referenced and there are no
// special expressions, no point in proceeding any further
PushProjector pushProject =
new PushProjector(origProj, joinRel.getCondition(), joinRel, preserveExprCondition);
if (pushProject.locateAllRefs()) {
return;
}
// create left and right projections, projecting only those
// fields referenced on each side
RelNode leftProjRel = pushProject.createProjectRefsAndExprs(joinRel.getLeft(), true, false);
RelNode rightProjRel = pushProject.createProjectRefsAndExprs(joinRel.getRight(), true, true);
// convert the join condition to reference the projected columns
RexNode newJoinFilter = null;
int[] adjustments = pushProject.getAdjustments();
if (joinRel.getCondition() != null) {
List<RelDataTypeField> projJoinFieldList = new ArrayList<RelDataTypeField>();
projJoinFieldList.addAll(joinRel.getSystemFieldList());
projJoinFieldList.addAll(leftProjRel.getRowType().getFieldList());
projJoinFieldList.addAll(rightProjRel.getRowType().getFieldList());
newJoinFilter =
pushProject.convertRefsAndExprs(joinRel.getCondition(), projJoinFieldList, adjustments);
}
// create a new joinrel with the projected children
JoinRel newJoinRel =
new JoinRel(
joinRel.getCluster(),
leftProjRel,
rightProjRel,
newJoinFilter,
joinRel.getJoinType(),
Collections.<String>emptySet(),
joinRel.isSemiJoinDone(),
joinRel.getSystemFieldList());
// put the original project on top of the join, converting it to
// reference the modified projection list
ProjectRel topProject = pushProject.createNewProject(newJoinRel, adjustments);
call.transformTo(topProject);
}
public void onMatch(RelOptRuleCall call) {
assert matches(call);
final JoinRel join = (JoinRel) call.rels[0];
final List<Integer> leftKeys = new ArrayList<Integer>();
final List<Integer> rightKeys = new ArrayList<Integer>();
RelNode right = join.getRight();
final RelNode left = join.getLeft();
RexNode remainingCondition =
RelOptUtil.splitJoinCondition(left, right, join.getCondition(), leftKeys, rightKeys);
assert leftKeys.size() == rightKeys.size();
final List<CorrelatorRel.Correlation> correlationList =
new ArrayList<CorrelatorRel.Correlation>();
if (leftKeys.size() > 0) {
final RelOptCluster cluster = join.getCluster();
final RexBuilder rexBuilder = cluster.getRexBuilder();
int k = 0;
RexNode condition = null;
for (Integer leftKey : leftKeys) {
Integer rightKey = rightKeys.get(k++);
final String dyn_inIdStr = cluster.getQuery().createCorrel();
final int dyn_inId = RelOptQuery.getCorrelOrdinal(dyn_inIdStr);
// Create correlation to say 'each row, set variable #id
// to the value of column #leftKey'.
correlationList.add(new CorrelatorRel.Correlation(dyn_inId, leftKey));
condition =
RelOptUtil.andJoinFilters(
rexBuilder,
condition,
rexBuilder.makeCall(
SqlStdOperatorTable.equalsOperator,
rexBuilder.makeInputRef(
right.getRowType().getFieldList().get(rightKey).getType(), rightKey),
rexBuilder.makeCorrel(
left.getRowType().getFieldList().get(leftKey).getType(), dyn_inIdStr)));
}
right = CalcRel.createFilter(right, condition);
}
RelNode newRel =
new CorrelatorRel(
join.getCluster(),
left,
right,
remainingCondition,
correlationList,
join.getJoinType());
call.transformTo(newRel);
}
public void onMatch(RelOptRuleCall call) {
JoinRel join = (JoinRel) call.rels[0];
List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(join.getChildExps()));
if (reduceExpressions(join, expList)) {
call.transformTo(
new JoinRel(
join.getCluster(),
join.getLeft(),
join.getRight(),
expList.get(0),
join.getJoinType(),
join.getVariablesStopped()));
// New plan is absolutely better than old plan.
call.getPlanner().setImportance(join, 0.0);
}
}
