AbstractPlanNode inlineAggregationApply(AbstractPlanNode plan) {
// check for an aggregation of the right form
if ((plan instanceof AggregatePlanNode) == false || (plan instanceof WindowFunctionPlanNode)) {
return plan;
}
assert (plan.getChildCount() == 1);
AggregatePlanNode aggplan = (AggregatePlanNode) plan;
// Assuming all AggregatePlanNode has not been inlined before this microoptimization
AbstractPlanNode child = aggplan.getChild(0);
// EE Currently support: seqscan + indexscan
if (child.getPlanNodeType() != PlanNodeType.SEQSCAN
&& child.getPlanNodeType() != PlanNodeType.INDEXSCAN
&& child.getPlanNodeType() != PlanNodeType.NESTLOOP
&& child.getPlanNodeType() != PlanNodeType.NESTLOOPINDEX) {
return plan;
}
if (child.getPlanNodeType() == PlanNodeType.INDEXSCAN) {
// Currently do not conflict with the optimized MIN/MAX
// because of the big amount of tests changed.
IndexScanPlanNode isp = (IndexScanPlanNode) child;
LimitPlanNode limit = (LimitPlanNode) isp.getInlinePlanNode(PlanNodeType.LIMIT);
if (limit != null && (aggplan.isTableMin() || aggplan.isTableMax())) {
// Optimized MIN/MAX
if (limit.getLimit() == 1 && limit.getOffset() == 0) {
return plan;
}
}
}
// Inline aggregate node
AbstractPlanNode parent = null;
if (aggplan.getParentCount() == 1) {
parent = aggplan.getParent(0);
}
child.addInlinePlanNode(aggplan);
child.clearParents();
if (parent != null) {
parent.replaceChild(aggplan, child);
}
return child;
}
