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push topn-filter to both sides of inner join (#33112)

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minghong
2024-04-01 22:46:28 +08:00
committed by GitHub
parent 7ace3ff6de
commit 1be38e798d
2 changed files with 61 additions and 20 deletions
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50
fe/fe-core/src/main/java/org/apache/doris/nereids/processor/post/TopNScanOpt.java
View File

@ -103,26 +103,44 @@ public class TopNScanOpt extends PlanPostProcessor {
}
private OlapScan findScanNodeBySlotReference(Plan root, SlotReference slot, boolean nullsFirst) {
// topn-filter cannot be pushed through right/full outer join if the first orderKey is nulls first
if (nullsFirst && root instanceof Join) {
Join join = (Join) root;
if (join.getJoinType().isRightOuterJoin() || join.getJoinType().isFullOuterJoin()) {
if (root instanceof PhysicalWindow) {
return null;
}
if (root instanceof OlapScan) {
if (root.getOutputSet().contains(slot)) {
return (OlapScan) root;
} else {
return null;
}
}
OlapScan target = null;
if (root instanceof OlapScan && root.getOutputSet().contains(slot)) {
return (OlapScan) root;
} else {
if (! root.children().isEmpty()) {
// for join and intersect, push topn-filter to their left child.
// TODO for union, topn-filter can be pushed down to all of its children.
Plan child = root.child(0);
if (!(child instanceof PhysicalWindow) && child.getOutputSet().contains(slot)) {
target = findScanNodeBySlotReference(child, slot, nullsFirst);
if (target != null) {
return target;
}
if (root instanceof Join) {
Join join = (Join) root;
if (nullsFirst && join.getJoinType().isOuterJoin()) {
// in fact, topn-filter can be pushed down to the left child of leftOuterJoin
// and to the right child of rightOuterJoin.
// but we have rule to push topn down to the left/right side. and topn-filter
// will be generated according to the inferred topn node.
return null;
}
// try to push to both left and right child
if (root.child(0).getOutputSet().contains(slot)) {
target = findScanNodeBySlotReference(root.child(0), slot, nullsFirst);
} else {
target = findScanNodeBySlotReference(root.child(1), slot, nullsFirst);
}
return target;
}
if (!root.children().isEmpty()) {
// TODO for set operator, topn-filter can be pushed down to all of its children.
Plan child = root.child(0);
if (child.getOutputSet().contains(slot)) {
target = findScanNodeBySlotReference(child, slot, nullsFirst);
if (target != null) {
return target;
}
}
}

31
regression-test/suites/nereids_tpch_p0/tpch/topn-filter.groovy
View File

@ -79,15 +79,15 @@ suite("topn-filter") {
qt_check_result2 "${multi_topn_desc}"
// do not use topn-filter
// push down topn-filter to both join children
explain {
sql """
select o_orderkey, c_custkey
from orders
join[broadcast] customer on o_custkey = c_custkey
join customer on o_custkey = c_custkey
order by c_custkey limit 2;
"""
notContains "TOPN OPT:"
contains "TOPN OPT:"
}
// push topn filter down through AGG
@ -123,10 +123,33 @@ suite("topn-filter") {
}
explain {
sql "select * from nation right outer join region on r_regionkey = n_regionkey order by n_regionkey nulls last limit 1; "
sql "select * from nation full outer join region on r_regionkey = n_regionkey order by n_regionkey nulls first limit 1; "
notContains "TOPN OPT:"
}
// this topn-filter is not generated from the top TOPN.
// topn
// +--left outer join
// +-- nation
// +-- region
// after topn push down:
// topn1
// +--left outer join
// +-- topn2
// +-- nation
// +-- region
// this topn-filter is generated by topn2, not topn1
explain {
sql "select * from nation left outer join region on r_regionkey = n_regionkey order by n_regionkey nulls first limit 1; "
contains "TOPN OPT:"
}
// TODO: support latter, push topn to right outer join
// explain {
// sql "select * from nation right outer join region on r_regionkey = n_regionkey order by n_regionkey nulls last limit 1; "
// contains "TOPN OPT:"
// }
explain {
sql "select * from nation right outer join region on r_regionkey = n_regionkey order by n_regionkey nulls last, n_name nulls first limit 1; "
contains "TOPN OPT:"