/**
* Return plan tree that augments 'root' with plan nodes that implement single-node evaluation of
* the AnalyticExprs in analyticInfo. This plan takes into account a possible hash partition of
* its input on 'groupingExprs'; if this is non-null, it returns in 'inputPartitionExprs' a subset
* of the grouping exprs which should be used for the aggregate hash partitioning during the
* parallelization of 'root'. TODO: when generating sort orders for the sort groups, optimize the
* ordering of the partition exprs (so that subsequent sort operations see the input sorted on a
* prefix of their required sort exprs) TODO: when merging sort groups, recognize equivalent exprs
* (using the equivalence classes) rather than looking for expr equality
*/
public PlanNode createSingleNodePlan(
PlanNode root, List<Expr> groupingExprs, List<Expr> inputPartitionExprs)
throws ImpalaException {
List<WindowGroup> windowGroups = collectWindowGroups();
for (int i = 0; i < windowGroups.size(); ++i) {
windowGroups.get(i).init(analyzer_, "wg-" + i);
}
List<SortGroup> sortGroups = collectSortGroups(windowGroups);
mergeSortGroups(sortGroups);
for (SortGroup g : sortGroups) {
g.init();
}
List<PartitionGroup> partitionGroups = collectPartitionGroups(sortGroups);
mergePartitionGroups(partitionGroups, root.getNumNodes());
orderGroups(partitionGroups);
if (groupingExprs != null) {
Preconditions.checkNotNull(inputPartitionExprs);
computeInputPartitionExprs(
partitionGroups, groupingExprs, root.getNumNodes(), inputPartitionExprs);
}
for (PartitionGroup partitionGroup : partitionGroups) {
for (int i = 0; i < partitionGroup.sortGroups.size(); ++i) {
root =
createSortGroupPlan(
root,
partitionGroup.sortGroups.get(i),
i == 0 ? partitionGroup.partitionByExprs : null);
}
}
// create equiv classes for newly added slots
analyzer_.createIdentityEquivClasses();
return root;
}
