Fixed bugs in CBO statistics calculation (#6537)

ydb-platform · Jul 11, 2024 · 526f29d · 526f29d
1 parent ec5a005
commit 526f29d
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Showing 7 changed files with 1,396 additions and 69 deletions.
diff --git a/ydb/core/kqp/opt/kqp_statistics_transformer.cpp b/ydb/core/kqp/opt/kqp_statistics_transformer.cpp
@@ -22,40 +22,53 @@ void InferStatisticsForReadTable(const TExprNode::TPtr& input, TTypeAnnotationCo
     const TKqpOptimizeContext& kqpCtx) {
 
     auto inputNode = TExprBase(input);
-    double nRows = 0;
-    int nAttrs = 0;
+    std::shared_ptr<TOptimizerStatistics> inputStats;
 
-    const TExprNode* path;
+    int nAttrs = 0;
+    bool readRange = false;
 
     if (auto readTable = inputNode.Maybe<TKqlReadTableBase>()) {
-        path = readTable.Cast().Table().Path().Raw();
+        inputStats = typeCtx->GetStats(readTable.Cast().Table().Raw());
         nAttrs = readTable.Cast().Columns().Size();
+
+        auto range = readTable.Cast().Range();
+        auto rangeFrom = range.From().Maybe<TKqlKeyTuple>();
+        auto rangeTo = range.To().Maybe<TKqlKeyTuple>();
+        if (rangeFrom && rangeTo) {
+            readRange = true;
+        }
     } else if (auto readRanges = inputNode.Maybe<TKqlReadTableRangesBase>()) {
-        path = readRanges.Cast().Table().Path().Raw();
+        inputStats = typeCtx->GetStats(readRanges.Cast().Table().Raw());
         nAttrs = readRanges.Cast().Columns().Size();
     } else {
         Y_ENSURE(false, "Invalid node type for InferStatisticsForReadTable");
     }
 
-    const auto& tableData = kqpCtx.Tables->ExistingTable(kqpCtx.Cluster, path->Content());
-    int totalAttrs = tableData.Metadata->Columns.size();
-    nRows = tableData.Metadata->RecordsCount;
-
-    double byteSize = tableData.Metadata->DataSize * (nAttrs / (double)totalAttrs);
-
-    auto keyColumns = TIntrusivePtr<TOptimizerStatistics::TKeyColumns>(new TOptimizerStatistics::TKeyColumns(tableData.Metadata->KeyColumnNames));
-    auto stats = std::make_shared<TOptimizerStatistics>(EStatisticsType::BaseTable, nRows, nAttrs, byteSize, 0.0, keyColumns);
-    if (kqpCtx.Config->OverrideStatistics.Get()) {
-        stats = OverrideStatistics(*stats, path->Content(), *kqpCtx.Config->OverrideStatistics.Get());
+    /**
+     * We need index statistics to calculate this in the future
+     * Right now we use very small estimates to make sure CBO picks Lookup Joins
+     * I.e. there can be a chain of lookup joins in OLTP scenario and we want to make
+     * sure the cardinality doesn't blow up and lookup joins are still being picked
+     */
+    double inputRows = inputStats->Nrows;
+    double nRows = inputRows;
+    if (readRange) {
+        nRows = 1;
     }
 
-    if (stats->ColumnStatistics) {
-        for (const auto& [columnName, metaData]: tableData.Metadata->Columns) {
-            stats->ColumnStatistics->Data[columnName].Type = metaData.Type;
-        }
-    }
+    double sizePerRow = inputStats->ByteSize / (inputRows==0?1:inputRows);
+    double byteSize = nRows * sizePerRow * (nAttrs / (double)inputStats->Ncols);
 
-    YQL_CLOG(TRACE, CoreDq) << "Infer statistics for read table, nrows: " << stats->Nrows << ", nattrs: " << stats->Ncols;
+    auto stats = std::make_shared<TOptimizerStatistics>(
+        EStatisticsType::BaseTable, 
+        nRows, 
+        nAttrs, 
+        byteSize, 
+        0.0, 
+        inputStats->KeyColumns,
+        inputStats->ColumnStatistics);
+
+    YQL_CLOG(TRACE, CoreDq) << "Infer statistics for read table, nrows: " << stats->Nrows << ", nattrs: " << stats->Ncols << ", byteSize: " << stats->ByteSize;
 
     typeCtx->SetStats(input.Get(), stats);
 }
@@ -81,7 +94,7 @@ void InferStatisticsForKqpTable(const TExprNode::TPtr& input, TTypeAnnotationCon
         stats = OverrideStatistics(*stats, path.Value(), *kqpCtx.Config->OverrideStatistics.Get());
     }
 
-    YQL_CLOG(TRACE, CoreDq) << "Infer statistics for table: " << path.Value() << ", nrows: " << stats->Nrows << ", nattrs: " << stats->Ncols << ", nKeyColumns: " << stats->KeyColumns->Data.size();
+    YQL_CLOG(TRACE, CoreDq) << "Infer statistics for table: " << path.Value() << ", nrows: " << stats->Nrows << ", nattrs: " << stats->Ncols << ", byteSize: " << stats->ByteSize << ", nKeyColumns: " << stats->KeyColumns->Data.size();
 
     typeCtx->SetStats(input.Get(), stats);
 }
@@ -103,7 +116,14 @@ void InferStatisticsForSteamLookup(const TExprNode::TPtr& input, TTypeAnnotation
     auto inputStats = typeCtx->GetStats(streamLookup.Table().Raw());
     auto byteSize = inputStats->ByteSize * (nAttrs / (double) inputStats->Ncols);
 
-    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(EStatisticsType::BaseTable, inputStats->Nrows, nAttrs, byteSize, 0, inputStats->KeyColumns));
+    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(
+        EStatisticsType::BaseTable, 
+        inputStats->Nrows, 
+        nAttrs, 
+        byteSize, 
+        0, 
+        inputStats->KeyColumns,
+        inputStats->ColumnStatistics));
 }
 
 /**
@@ -134,7 +154,14 @@ void InferStatisticsForLookupTable(const TExprNode::TPtr& input, TTypeAnnotation
         byteSize = 10;
     }
 
-    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(EStatisticsType::BaseTable, nRows, nAttrs, byteSize, 0, inputStats->KeyColumns));
+    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(
+        EStatisticsType::BaseTable, 
+        nRows,
+        nAttrs, 
+        byteSize, 
+        0, 
+        inputStats->KeyColumns,
+        inputStats->ColumnStatistics));
 }
 
 /**
@@ -151,7 +178,8 @@ void InferStatisticsForRowsSourceSettings(const TExprNode::TPtr& input, TTypeAnn
         return;
     }
 
-    double nRows = inputStats->Nrows;
+    double inputRows =  inputStats->Nrows;
+    double nRows = inputRows;
 
     // Check if we have a range expression, in that case just assign a single row to this read
     // We don't currently check the size of an index lookup
@@ -165,10 +193,19 @@ void InferStatisticsForRowsSourceSettings(const TExprNode::TPtr& input, TTypeAnn
     }
 
     int nAttrs = sourceSettings.Columns().Size();
+
+    double sizePerRow = inputStats->ByteSize / (inputRows==0?1:inputRows);
+    double byteSize = nRows * sizePerRow * (nAttrs / (double)inputStats->Ncols);
     double cost = inputStats->Cost;
-    double byteSize = inputStats->ByteSize * (nAttrs / (double)inputStats->Ncols);
 
-    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(EStatisticsType::BaseTable, nRows, nAttrs, byteSize, cost, inputStats->KeyColumns));
+    typeCtx->SetStats(input.Get(), std::make_shared<TOptimizerStatistics>(
+        EStatisticsType::BaseTable, 
+        nRows, 
+        nAttrs, 
+        byteSize, 
+        cost, 
+        inputStats->KeyColumns, 
+        inputStats->ColumnStatistics));
 }
 
 /**
@@ -199,7 +236,8 @@ void InferStatisticsForReadTableIndexRanges(const TExprNode::TPtr& input, TTypeA
         inputStats->Ncols, 
         inputStats->ByteSize, 
         inputStats->Cost, 
-        indexColumnsPtr);
+        indexColumnsPtr,
+        inputStats->ColumnStatistics);
 
     typeCtx->SetStats(input.Get(), stats);
 

diff --git a/ydb/core/kqp/ut/join/data/join_order/tpcc.json b/ydb/core/kqp/ut/join/data/join_order/tpcc.json
@@ -0,0 +1,13 @@
+{
+  "op_name": "InnerJoin (Map)",
+  "args": [
+    {
+        "op_name": "TableLookup",
+        "table": "stock"
+    },
+    {
+        "op_name": "TableRangeScan",
+        "table": "order_line"
+    }
+  ]
+}
diff --git a/ydb/core/kqp/ut/join/data/join_order/tpch9_1000s.json b/ydb/core/kqp/ut/join/data/join_order/tpch9_1000s.json
@@ -1,49 +1,49 @@
 {
-  "op_name": "InnerJoin (Grace)",
+  "op_name": "InnerJoin (MapJoin)",
   "args": [
-    {
-      "op_name": "InnerJoin (Grace)",
-      "args": [
-        {
-          "op_name": "TableFullScan",
-          "table": "orders"
-        },
-        {
+      {
           "op_name": "InnerJoin (Grace)",
           "args": [
-            {
-              "op_name": "TableFullScan",
-              "table": "lineitem"
-            },
-            {
-              "op_name": "InnerJoin (Grace)",
-              "args": [
-                {
+              {
                   "op_name": "TableFullScan",
-                  "table": "partsupp"
-                },
-                {
+                  "table": "orders"
+              },
+              {
+                  "op_name": "InnerJoin (Grace)",
+                  "args": [
+                      {
+                          "op_name": "TableFullScan",
+                          "table": "lineitem"
+                      },
+                      {
+                          "op_name": "InnerJoin (MapJoin)",
+                          "args": [
+                              {
+                                  "op_name": "TableFullScan",
+                                  "table": "partsupp"
+                              },
+                              {
+                                  "op_name": "TableFullScan",
+                                  "table": "part"
+                              }
+                          ]
+                      }
+                  ]
+              }
+          ]
+      },
+      {
+          "op_name": "InnerJoin (MapJoin)",
+          "args": [
+              {
+                  "op_name": "TableFullScan",
+                  "table": "supplier"
+              },
+              {
                   "op_name": "TableFullScan",
-                  "table": "part"
-                }
-              ]
-            }
+                  "table": "nation"
+              }
           ]
-        }
-      ]
-    },
-    {
-      "op_name": "InnerJoin (MapJoin)",
-      "args": [
-        {
-          "op_name": "TableFullScan",
-          "table": "supplier"
-        },
-        {
-          "op_name": "TableFullScan",
-          "table": "nation"
-        }
-      ]
-    }
+      }
   ]
-}
+}
diff --git a/ydb/core/kqp/ut/join/data/queries/tpcc.sql b/ydb/core/kqp/ut/join/data/queries/tpcc.sql
@@ -0,0 +1,8 @@
+SELECT COUNT(DISTINCT (s.S_I_ID)) AS STOCK_COUNT
+FROM `/Root/test/tpcc/order_line` as ol INNER JOIN `/Root/test/tpcc/stock` as s ON s.S_I_ID = ol.OL_I_ID
+WHERE ol.OL_W_ID = 1
+AND ol.OL_D_ID = 10
+AND ol.OL_O_ID < 3000
+AND ol.OL_O_ID >= 2900
+AND s.S_W_ID = 1
+AND s.S_QUANTITY < 15