| // ********************************************************************** |
| // @@@ START COPYRIGHT @@@ |
| // |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| // |
| // @@@ END COPYRIGHT @@@ |
| // ********************************************************************** |
| |
| // *********************************************************************** |
| // |
| // File: QRDescriptorExtentions.cpp |
| // |
| // Description: QRDescriptor methods used only by MXCMP. |
| // These methods are used when constructing an ItemExpr |
| // expression tree from rewrite instructions in the |
| // result descriptor. |
| // |
| // Created: 08/24/2010 |
| // *********************************************************************** |
| |
| #include "QRDescriptor.h" |
| #include "QRLogger.h" |
| #include "ItemExpr.h" |
| #include "ItemFunc.h" |
| #include "ItemColRef.h" |
| #include "ItemFunc.h" |
| #include "ItemLog.h" |
| #include "ItemArith.h" |
| #include "NumericType.h" |
| #include "MVCandidates.h" |
| |
| // *************************************************************** |
| // Use the ref attribute to find the ValueID the element was |
| // constructed from, and from the ValueID get the ItemExpr |
| // object itself. |
| // *************************************************************** |
| ItemExpr* QRExplicitExpr::findItemExpr() |
| { |
| CollIndex id = getRefNum(); |
| assertLogAndThrow(CAT_SQL_COMP_QR_DESC_GEN, LL_MVQR_FAIL, |
| id!=0, QRLogicException, |
| "findItemExpr() called with zero ValueID."); |
| ValueId vid(id); |
| return vid.getItemExpr(); |
| } |
| |
| // *************************************************************** |
| // This is a back-join or Outside column. |
| // *************************************************************** |
| ItemExpr* QRColumn::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| // Get the fully qualified table name by stripping the column name and last |
| // dot from the fq column name, then create a CorrName to use in |
| // constructing a ColRefName for the ColReference. |
| NAString fqTblName(fqColumnName_); |
| fqTblName.resize(fqColumnName_.length() - columnName_.length() - 1); |
| QualifiedName tblQualName(fqTblName, 3, heap); |
| NAString corrNameStr; |
| // Add special correlation name if the column is from a backjoin table. |
| if (scanhash->getFirstValue(&tableId_)) |
| (corrNameStr = MVCandidates::BACKJOIN_CORRNAME_PREFIX).append(tableId_); |
| CorrName tblCorrName(tblQualName, heap, corrNameStr); |
| return new(heap) ColReference(new(heap) |
| ColRefName(columnName_, tblCorrName, heap)); |
| } |
| |
| // *************************************************************** |
| // This is a column of the MV. |
| // *************************************************************** |
| ItemExpr* QRMVColumn::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| QualifiedName mvQualName(mvName, 3, heap); |
| CorrName mvCorrName(mvQualName, heap); |
| return new(heap) ColReference(new(heap) |
| ColRefName(getMVColName(), mvCorrName, heap)); |
| } |
| |
| // *************************************************************** |
| // This is a scalar value - create a new SystemLiteral for it. |
| // *************************************************************** |
| ItemExpr* QRScalarValue::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| ConstValue* cv = NULL; |
| ItemExpr* ie = findItemExpr(); |
| OperatorTypeEnum op = ie->getOperatorType(); |
| if (op == ITM_CACHE_PARAM) |
| cv = ((ConstantParameter*)ie)->getConstVal(); |
| else |
| { |
| assertLogAndThrow(CAT_SQL_COMP_QR_DESC_GEN, LL_MVQR_FAIL, op == ITM_CONSTANT, |
| QRLogicException, "Expecting a ConstValue object."); |
| cv = (ConstValue*)ie; |
| } |
| return new(heap) SystemLiteral(cv->getType(), cv->getConstValue(), cv->getStorageSize()); |
| } |
| |
| // *************************************************************** |
| // This is a NULL value - much easier than the generic literal case. |
| // *************************************************************** |
| ItemExpr* QRNullVal::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| return new(heap) SystemLiteral(); |
| } |
| |
| // *************************************************************** |
| // A Binary operator - Dup the object and call recursively |
| // for the operands. |
| // *************************************************************** |
| ItemExpr* QRBinaryOper::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| ItemExpr* oldObj = findItemExpr(); |
| ItemExpr* newObj = oldObj->copyTopNode(NULL, heap); |
| newObj->child(0) = getFirstOperand()->toItemExpr(mvName, heap, scanhash); |
| newObj->child(1) = getSecondOperand()->toItemExpr(mvName, heap, scanhash); |
| return newObj; |
| } |
| |
| // *************************************************************** |
| // A Unary operator - Dup the object and call recursively |
| // for the operand. |
| // *************************************************************** |
| ItemExpr* QRUnaryOper::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| ItemExpr* oldObj = findItemExpr(); |
| ItemExpr* newObj = oldObj->copyTopNode(NULL, heap); |
| newObj->child(0) = getOperand()->toItemExpr(mvName, heap, scanhash); |
| return newObj; |
| } |
| |
| // *************************************************************** |
| // A Function - Dup the object and call recursively |
| // for the arguments. |
| // If a ValueId is not referenced, then its an aggregate |
| // function for rollup - construct it manually. |
| // *************************************************************** |
| ItemExpr* QRFunction::toItemExpr(const NAString& mvName, CollHeap* heap, |
| TableNameScanHash* scanhash) |
| { |
| ItemExpr* newObj = NULL; |
| |
| // Is a ValueId referenced? |
| if (getRefNum() != 0) |
| { |
| // Yes, this is the normal case. |
| ItemExpr* oldObj = findItemExpr(); |
| newObj = oldObj->copyTopNode(NULL, heap); |
| const NAPtrList<QRExplicitExprPtr>& args = getArguments(); |
| |
| // For StdDev and Variance, all args must be double precision. |
| // otherwise, ScalarVariance::preCodeGen will GenAssert. |
| NABoolean isScalarVariance = (getFunctionName() == "Scalar Variance" || |
| getFunctionName() == "Scalar Stddev" ); |
| NAType *dbl = new(heap) SQLDoublePrecision(heap, FALSE); |
| |
| // Loop over the arguments and call recursively. |
| for (CollIndex i=0; i<args.entries(); i++) |
| { |
| if (args[i] != NULL) |
| { |
| ItemExpr* argument = args[i]->toItemExpr(mvName, heap, scanhash); |
| |
| if (isScalarVariance) |
| argument = new(heap) Cast(argument, dbl); |
| |
| newObj->child(i) = argument; |
| } |
| } |
| } |
| else |
| { |
| // In a Rollup case, we generate a new aggregate function, |
| // so it does not have a ref attribute. |
| assertLogAndThrow(CAT_SQL_COMP_QR_DESC_GEN, LL_MVQR_FAIL, |
| isAnAggregate(), QRLogicException, |
| "Only Aggregate functions are allowed not to reference a ValueID."); |
| OperatorTypeEnum ieEnum = NO_OPERATOR_TYPE; |
| NABoolean isDistinct = FALSE; |
| |
| ItemExpr* argument = getArguments()[0]->toItemExpr(mvName, heap, scanhash); |
| switch(getAggregateFunc()) |
| { |
| case AFT_COUNTSTAR: |
| ieEnum = ITM_COUNT; |
| break; |
| case AFT_COUNT: |
| ieEnum = ITM_COUNT_NONULL; |
| break; |
| case AFT_SUM: |
| ieEnum = ITM_SUM; |
| break; |
| case AFT_MIN: |
| ieEnum = ITM_MIN; |
| break; |
| case AFT_MAX: |
| ieEnum = ITM_MAX; |
| break; |
| case AFT_COUNT_DISTINCT: |
| ieEnum = ITM_COUNT_NONULL; |
| isDistinct = TRUE; |
| break; |
| case AFT_SUM_DISTINCT: |
| ieEnum = ITM_SUM; |
| isDistinct = TRUE; |
| break; |
| case AFT_ONE_ROW: |
| ieEnum = ITM_ONE_ROW; |
| break; |
| case AFT_ONEROW: |
| ieEnum = ITM_ONEROW; |
| break; |
| case AFT_ONE_TRUE: |
| ieEnum = ITM_ONE_TRUE; |
| break; |
| case AFT_ANY_TRUE: |
| ieEnum = ITM_ANY_TRUE; |
| break; |
| |
| case AFT_COUNT_ON_GROUPING: |
| case AFT_SUM_ON_GROUPING: |
| { |
| // These are the special cases of rewriting COUNT and SUM on an |
| // MV grouping column. Instead of providing an explicit expression, |
| // QMS provides these internal "functions", which are implemented here. |
| // These special functions have 2 arguments, where the second is the |
| // MV's COUNT(*) column (referenced below as countStar). |
| QRExplicitExprPtr countStarRewrite = getArguments()[1]; |
| ItemExpr* countStar = countStarRewrite->toItemExpr(mvName, heap, scanhash); |
| |
| if (getAggregateFunc() == AFT_COUNT_ON_GROUPING) |
| { |
| // COUNT(g) => SUM( CASE WHEN g IS NULL THEN 0 ELSE countStar END ) |
| ieEnum = ITM_SUM; |
| argument = new(heap) |
| Case(NULL, new(heap) |
| IfThenElse(new(heap) UnLogic(ITM_IS_NULL, argument), |
| new(heap) SystemLiteral(0), |
| countStar)); |
| } |
| else |
| { |
| // SUM(g) => SUM(g*countStar) |
| ieEnum = ITM_SUM; |
| argument = new(heap) BiArith(ITM_TIMES, argument, countStar); |
| } |
| } |
| |
| } // end switch() |
| newObj = new(heap) Aggregate(ieEnum, argument, isDistinct); |
| } |
| |
| return newObj; |
| } |
