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[KQP RBO] Add group by on expressions #28922

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Merged
merged 1 commit into from
Nov 17, 2025
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[KQP RBO] Add group by on expressions #28922

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94 changes: 71 additions & 23 deletions ydb/core/kqp/opt/rbo/kqp_rbo_transformer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -151,8 +151,9 @@ void BuildSimpleMapElementLambda(TExprNode::TPtr resultExpr, const TVector<std::
TExprNode::TPtr BuildExpressionMap(TExprNode::TPtr resultExpr,
const TVector<std::pair<TInfoUnit, TExprNode::TPtr>>& aggFieldsExpressionsMap,
const TVector<std::pair<TInfoUnit, TInfoUnit>>& aggFieldsRenamesMap,
const TVector<std::pair<TInfoUnit, TInfoUnit>>& groupByKeysRenamesMap, TExprContext& ctx,
TPositionHandle pos) {
const TVector<std::pair<TInfoUnit, TInfoUnit>>& groupByKeysRenamesMap,
const THashMap<uint32_t, std::pair<TInfoUnit, TExprNode::TPtr>>& groupByKeysExpressionsMap,
TExprContext& ctx, TPositionHandle pos) {
// Add expressions
TVector<TExprNode::TPtr> mapElements;
for (const auto& [colName, expr] : aggFieldsExpressionsMap) {
Expand All @@ -171,6 +172,19 @@ TExprNode::TPtr BuildExpressionMap(TExprNode::TPtr resultExpr,
BuildSimpleMapElementLambda(resultExpr, aggFieldsRenamesMap, mapElements, ctx, pos);
BuildSimpleMapElementLambda(resultExpr, groupByKeysRenamesMap, mapElements, ctx, pos);

// Add expressions for group by keys.
for (const auto& [_, pair] : groupByKeysExpressionsMap) {
// clang-format off
mapElements.push_back(Build<TKqpOpMapElementLambda>(ctx, pos)
.Input(resultExpr)
.Variable()
.Value(pair.first.GetFullName())
.Build()
.Lambda(pair.second)
.Done().Ptr());
// clang-format on
}

// clang-format off
return Build<TKqpOpMap>(ctx, pos)
.Input(resultExpr)
Expand All @@ -184,8 +198,8 @@ TExprNode::TPtr BuildExpressionMap(TExprNode::TPtr resultExpr,
// clang-format on
}

void BuildMapElementRename(TExprNode::TPtr resultExpr, const TVector<std::pair<TInfoUnit, TInfoUnit>>& renamesMap, TVector<TExprNode::TPtr>& mapElements,
TExprContext& ctx, TPositionHandle pos) {
void BuildMapElementRename(TExprNode::TPtr resultExpr, const TVector<std::pair<TInfoUnit, TInfoUnit>>& renamesMap,
TVector<TExprNode::TPtr>& mapElements, TExprContext& ctx, TPositionHandle pos) {
for (const auto& [colName, newColName] : renamesMap) {
// clang-format off
mapElements.push_back(Build<TKqpOpMapElementRename>(ctx, pos)
Expand Down Expand Up @@ -552,20 +566,38 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
filterExpr = Build<TKqpOpEmptySource>(ctx, node->Pos()).Done().Ptr();
}

// FIXME: Group by key can be an expression, we need to handle this case
THashSet<TString> aggregationColumnsRequireCastToPgType;
TVector<std::pair<TInfoUnit, TInfoUnit>> groupByKeysRenamesMap;
THashMap<uint32_t, std::pair<TInfoUnit, TExprNode::TPtr>> groupByKeysExpressionsMap;
TVector<TInfoUnit> groupByKeys;
auto groupOps = GetSetting(setItem->Tail(), "group_exprs");
if (groupOps) {
const auto groupByList = groupOps->TailPtr();
for (ui32 i = 0; i < groupByList->ChildrenSize(); ++i) {
auto lambda = TCoLambda(ctx.DeepCopyLambda(*(groupByList->ChildPtr(i)->Child(1))));
auto body = lambda.Body().Ptr();
TVector<TInfoUnit> keys;
GetAllMembers(body, keys);
groupByKeys.insert(groupByKeys.end(), keys.begin(), keys.end());
for (const auto &infoUnit : keys) {
groupByKeysRenamesMap.push_back({infoUnit, infoUnit});
auto pgResolvedOp = GetPgCallable(lambda.Body().Ptr(), "PgResolvedOp");
// Expression for group by keys.
if (pgResolvedOp) {
auto fromPg = ctx.NewCallable(node->Pos(), "FromPg", {pgResolvedOp});

// clang-format off
auto groupExprLambda = Build<TCoLambda>(ctx, node->Pos())
.Args(lambda.Args())
.Body(fromPg)
.Done().Ptr();
// clang-format on

const auto newColName = TInfoUnit(GenerateUniqueColumnName("_group_expr_"));
groupByKeysExpressionsMap[i] = std::make_pair(newColName, groupExprLambda);
groupByKeys.push_back(newColName);
} else {
TVector<TInfoUnit> keys;
GetAllMembers(body, keys);
Y_ENSURE(keys.size() == 1, "Invalid size of the group keys.");
const auto groupKeyName = keys.front();
groupByKeys.push_back(groupKeyName);
groupByKeysRenamesMap.push_back({groupKeyName, groupKeyName});
}
}
}
Expand All @@ -575,8 +607,6 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
Y_ENSURE(result);
auto finalType = node->GetTypeAnn()->Cast<TListExprType>()->GetItemType()->Cast<TStructExprType>();

// This is a hack to enable convertion for aggregation columns.
THashSet<TString> aggregationColumns;
THashSet<TString> columnNames;
// Collect PgAgg for each result item at first pass.
TVector<TExprNode::TPtr> aggTraitsList;
Expand All @@ -598,14 +628,18 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
TVector<TInfoUnit> originalColNames;
GetAllMembers(pgAgg, originalColNames);
auto pgResolvedOp = GetPgCallable(lambda.Body().Ptr(), "PgResolvedOp");
//Y_ENSURE(originalColNames.size() > 1 && pgResolvedOp, "Invalid column size for aggregation columns.");

auto originalColName = originalColNames.front();
auto renamedColName = originalColName;

if (pgResolvedOp) {
auto fromPg = ctx.NewCallable(node->Pos(), "FromPg", {pgResolvedOp});
auto exprLambda = Build<TCoLambda>(ctx, node->Pos()).Args(lambda.Args()).Body(fromPg).Done().Ptr();
// clang-format off
auto exprLambda = Build<TCoLambda>(ctx, node->Pos())
.Args(lambda.Args())
.Body(fromPg)
.Done().Ptr();
// clang-format on

// Just any unique name for expression result, physical plan should be AsSturct(`unique_name (expression))
originalColName = TInfoUnit(GenerateUniqueColumnName("_expr_"));
Expand All @@ -623,7 +657,7 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
columnNames.insert(renamedColName.GetFullName());
Y_ENSURE(!GetAtom(pgAgg->ChildPtr(1), "distinct"), "Aggregation on distinct is not supported");

aggregationColumns.insert(resultColName);
aggregationColumnsRequireCastToPgType.insert(resultColName);
const TString aggFuncName = TString(pgAgg->ChildPtr(0)->Content());
auto aggregationTraits = BuildAggregationTraits(renamedColName.GetFullName(), resultColName, aggFuncName,
aggFuncResultType, ctx, node->Pos());
Expand All @@ -637,7 +671,7 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
}
// This case covers distinct all on just columns without aggregation functions.
} else if (!pgAgg && distinctAll) {
aggregationColumns.insert(resultColName);
aggregationColumnsRequireCastToPgType.insert(resultColName);
Y_ENSURE(aggFuncResultType, "Cannot find type for aggregation result.");
TVector<TInfoUnit> originalColNames;
GetAllMembers(resultItem->ChildPtr(2), originalColNames);
Expand All @@ -658,9 +692,10 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
if (needRenameMap) {
resultExpr = BuildRenameMap(resultExpr, aggFieldsRenamesMap, groupByKeysRenamesMap, ctx, node->Pos());
}
// In case we have an expression for aggregation - f(a + b ..)
if (!aggFieldsExpressionsMap.empty()) {
resultExpr = BuildExpressionMap(resultExpr, aggFieldsExpressionsMap, aggFieldsRenamesMap, groupByKeysRenamesMap, ctx, node->Pos());
// In case we have an expression for aggregation - f(a + b ..) or group by.
if (!aggFieldsExpressionsMap.empty() || !groupByKeysExpressionsMap.empty()) {
resultExpr = BuildExpressionMap(resultExpr, aggFieldsExpressionsMap, aggFieldsRenamesMap, groupByKeysRenamesMap,
groupByKeysExpressionsMap, ctx, node->Pos());
}
resultExpr = BuildAggregate(resultExpr, groupByKeys, aggTraitsList, distinctAll, ctx, node->Pos());
}
Expand All @@ -671,7 +706,6 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
}

finalColumnOrder.clear();
THashMap<TString, TExprNode::TPtr> aggProjectionMap;

for (auto resultItem : result->Child(1)->Children()) {
auto column = resultItem->Child(0);
Expand All @@ -691,7 +725,7 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,

bool needPgCast = (expectedType->GetId() != actualPgTypeId);
auto lambda = TCoLambda(ctx.DeepCopyLambda(*(resultItem->Child(2))));
bool needPgCastForAgg = aggregationColumns.count(columnName);
bool needPgCastForAgg = aggregationColumnsRequireCastToPgType.count(columnName);

auto pgAgg = GetPgCallable(lambda.Body().Ptr(), "PgAgg");
if (pgAgg) {
Expand All @@ -715,14 +749,28 @@ TExprNode::TPtr RewritePgSelect(const TExprNode::TPtr &node, TExprContext &ctx,
// Eliminate `PgGroupRef` from projection lambda.
auto pgGroupRef = GetPgCallable(lambda.Body().Ptr(), "PgGroupRef");
if (pgGroupRef) {
Y_ENSURE(pgGroupRef->ChildrenSize() == 4);
TString columnName;
if (pgGroupRef->ChildrenSize() == 4) {
columnName = TString(pgGroupRef->ChildPtr(3)->Content());
} else if (pgGroupRef->ChildrenSize() == 3) {
// In this case we can get a column name from group expr map
const auto groupByKeyExprId = FromString<uint32_t>(TString(pgGroupRef->ChildPtr(2)->Content()));
auto it = groupByKeysExpressionsMap.find(groupByKeyExprId);
Y_ENSURE(it != groupByKeysExpressionsMap.end(), "Group by key expression has invalid content.");
columnName = it->second.first.GetFullName();
// Always need a pg cast for expressions.
needPgCast = true;
} else {
Y_ENSURE(false, "Invalid children size for `pgGroupRef`");
}

// clang-format off
lambda = Build<TCoLambda>(ctx, node->Pos())
.Args(lambda.Args())
.Body<TCoMember>()
.Struct(lambda.Args().Arg(0))
.Name<TCoAtom>()
.Value(pgGroupRef->ChildPtr(3)->Content())
.Value(columnName)
.Build()
.Build()
.Done();
Expand Down
20 changes: 19 additions & 1 deletion ydb/core/kqp/ut/rbo/kqp_rbo_ut.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -609,6 +609,21 @@ Y_UNIT_TEST_SUITE(KqpRbo) {
SET TablePathPrefix = "/Root/";
select sum(t1.a + 1 + t1.c) as sumExpr0, sum(t1.c + 2) as sumExpr1 from t1 group by t1.b order by sumExpr0;
)",
R"(
--!syntax_pg
SET TablePathPrefix = "/Root/";
select sum(t1.c) as sum0, sum(t1.a + 3) as sum1 from t1 group by t1.b + 1 order by sum0;
)",
R"(
--!syntax_pg
SET TablePathPrefix = "/Root/";
select sum(t1.c) as sum0, t1.b + 1, t1.c + 2 from t1 group by t1.b + 1, t1.c + 2 order by sum0;
)",
R"(
--!syntax_pg
SET TablePathPrefix = "/Root/";
select sum(t1.c + 2) as sum0 from t1 group by t1.b + t1.a order by sum0;
)",
};

std::vector<std::string> results = {
Expand All @@ -625,7 +640,10 @@ Y_UNIT_TEST_SUITE(KqpRbo) {
R"([["0";"2"];["1";"1"];["2";"2"];["3";"1"];["4";"2"]])",
R"([["4";"4"];["6";"6"]])",
R"([["0";"4"];["1";"3"]])",
R"([["10";"8"];["15";"12"]])"
R"([["10";"8"];["15";"12"]])",
R"([["4";"10"];["6";"15"]])",
R"([["4";"2";"4"];["6";"3";"4"]])",
R"([["4"];["8"];["8"]])"
};

for (ui32 i = 0; i < queries.size(); ++i) {
Expand Down
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