Consider used columns in index chooser

KIKIMR-10864

2 files changed, 17 insertions, 7 deletions

diff --git a/ydb/core/kqp/opt/logical/kqp_opt_log_ranges_predext.cpp b/ydb/core/kqp/opt/logical/kqp_opt_log_ranges_predext.cpp
index a60308ebdd..b6a0a87f95 100644
--- a/ydb/core/kqp/opt/logical/kqp_opt_log_ranges_predext.cpp
+++ b/ydb/core/kqp/opt/logical/kqp_opt_log_ranges_predext.cpp
@@ -265,14 +265,23 @@ TExprBase KqpPushExtractedPredicateToReadTable(TExprBase node, TExprContext& ctx
 
     if (!indexName.IsValid() && !readSettings.ForcePrimary && kqpCtx.Config->IndexAutoChooserMode != NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_DISABLED) {
         using TIndexComparisonKey = std::tuple<bool, size_t, bool, size_t, bool>;
-        auto calcKey = [&](NYql::IPredicateRangeExtractor::TBuildResult buildResult, size_t descriptionKeyColumns, bool needsJoin) -> TIndexComparisonKey {
+        auto calcNeedsJoin = [&] (const TKikimrTableMetadataPtr& keyTable) -> bool {
+            bool needsJoin = false;
+            for (auto&& column : read.Columns()) {
+                if (!keyTable->Columns.contains(column.Value())) {
+                    needsJoin = true;
+                }
+            }
+            return needsJoin;
+        };
 
+        auto calcKey = [&](NYql::IPredicateRangeExtractor::TBuildResult buildResult, size_t descriptionKeyColumns, bool needsJoin) -> TIndexComparisonKey {
             return std::make_tuple(
                 buildResult.PointPrefixLen >= descriptionKeyColumns,
                 buildResult.PointPrefixLen,
                 buildResult.UsedPrefixLen >= descriptionKeyColumns,
                 buildResult.UsedPrefixLen,
-                needsJoin);
+                !needsJoin);
         };
 
         TMaybe<TString> chosenIndex;
@@ -284,15 +293,16 @@ TExprBase KqpPushExtractedPredicateToReadTable(TExprBase node, TExprContext& ctx
                 if (index.Type != TIndexDescription::EType::GlobalAsync) {
                     auto& tableDesc = kqpCtx.Tables->ExistingTable(kqpCtx.Cluster, mainTableDesc.Metadata->GetIndexMetadata(TString(index.Name)).first->Name);
                     auto buildResult = extractor->BuildComputeNode(tableDesc.Metadata->KeyColumnNames, ctx, typesCtx);
+                    bool needsJoin = calcNeedsJoin(tableDesc.Metadata);
 
-                    if (kqpCtx.Config->IndexAutoChooserMode == NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_ONLY_FULL_KEY && buildResult.PointPrefixLen < index.KeyColumns.size()) {
+                    if (needsJoin && kqpCtx.Config->IndexAutoChooserMode == NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_ONLY_FULL_KEY && buildResult.PointPrefixLen < index.KeyColumns.size()) {
                         continue;
                     }
-                    if (kqpCtx.Config->IndexAutoChooserMode == NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_ONLY_POINTS && buildResult.PointPrefixLen == 0) {
+                    if (needsJoin && kqpCtx.Config->IndexAutoChooserMode == NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_ONLY_POINTS && buildResult.PointPrefixLen == 0) {
                         continue;
                     }
 
-                    auto key = calcKey(buildResult, index.KeyColumns.size(), true);
+                    auto key = calcKey(buildResult, index.KeyColumns.size(), needsJoin);
                     if (key > maxKey) {
                         maxKey = key;
                         chosenIndex = index.Name;
diff --git a/ydb/core/kqp/ut/opt/kqp_ne_ut.cpp b/ydb/core/kqp/ut/opt/kqp_ne_ut.cpp
index 89b2f10a18..adc7addeac 100644
--- a/ydb/core/kqp/ut/opt/kqp_ne_ut.cpp
+++ b/ydb/core/kqp/ut/opt/kqp_ne_ut.cpp
@@ -3905,7 +3905,7 @@ Y_UNIT_TEST_SUITE(KqpNewEngine) {
     Y_UNIT_TEST(AutoChooseIndex) {
         TKikimrSettings settings;
         NKikimrConfig::TAppConfig appConfig;
-        appConfig.MutableTableServiceConfig()->SetIndexAutoChooseMode(NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_MAX_USED_PREFIX);
+        appConfig.MutableTableServiceConfig()->SetIndexAutoChooseMode(NKikimrConfig::TTableServiceConfig_EIndexAutoChooseMode_ONLY_POINTS);
         settings.SetAppConfig(appConfig);
 
         TKikimrRunner kikimr(settings);
@@ -3919,7 +3919,7 @@ Y_UNIT_TEST_SUITE(KqpNewEngine) {
 
         auto result = session.ExecuteDataQuery(R"(
             --!syntax_v1
-            SELECT * FROM `/Root/SecondaryKeys` WHERE Fk <= 1;
+            SELECT Fk, Key FROM `/Root/SecondaryKeys` WHERE Fk <= 1;
         )", TTxControl::BeginTx(TTxSettings::SerializableRW()), querySettings).GetValueSync();
         AssertSuccessResult(result);
         AssertTableReads(result, "/Root/SecondaryKeys/Index/indexImplTable", 1);