/**
* This is invoked when a NOT function is got. It's usually the case NOT<IN optimizer>
* This function will simple turn the semi join to anti join
*
*/
void InSub::handleNot()
{
ParseTree *pt = fGwip.ptWorkStack.top();
ExistsFilter *subFilter = dynamic_cast<ExistsFilter*>(pt->data());
idbassert(subFilter);
subFilter->notExists(true);
SCSEP csep = subFilter->sub();
const ParseTree* ptsub = csep->filters();
if (ptsub)
ptsub->walk(makeAntiJoin);
ptsub = csep->having();
if (ptsub)
ptsub->walk(makeAntiJoin);
}
/** MySQL transform (NOT) IN subquery to (NOT) EXIST
*
*/
execplan::ParseTree* InSub::transform()
{
if (!fFunc)
return NULL;
// @todo need to handle scalar IN and BETWEEN specially
// this blocks handles only one subselect scalar
// arg[0]: column | arg[1]: subselect
//assert (fFunc->argument_count() == 2 && fGwip.rcWorkStack.size() >= 2);
if (fFunc->argument_count() != 2 || fGwip.rcWorkStack.size() < 2)
{
fGwip.fatalParseError = true;
fGwip.parseErrorText = "Unsupported item in IN subquery";
return NULL;
}
ReturnedColumn* rhs = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
delete rhs;
ReturnedColumn* lhs = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
delete lhs;
fSub = (Item_subselect*)(fFunc->arguments()[1]);
idbassert(fSub && fFunc);
SCSEP csep (new CalpontSelectExecutionPlan());
csep->sessionID(fGwip.sessionid);
csep->location(CalpontSelectExecutionPlan::WHERE);
csep->subType (CalpontSelectExecutionPlan::IN_SUBS);
// gwi for the sub query
gp_walk_info gwi;
gwi.thd = fGwip.thd;
gwi.subQuery = this;
// @4827 merge table list to gwi in case there is FROM sub to be referenced
// in the FROM sub
gwi.derivedTbCnt = fGwip.derivedTbList.size();
uint32_t tbCnt = fGwip.tbList.size();
gwi.tbList.insert(gwi.tbList.begin(), fGwip.tbList.begin(), fGwip.tbList.end());
gwi.derivedTbList.insert(gwi.derivedTbList.begin(), fGwip.derivedTbList.begin(), fGwip.derivedTbList.end());
if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep) != 0)
{
fGwip.fatalParseError = true;
if (gwi.fatalParseError && !gwi.parseErrorText.empty())
fGwip.parseErrorText = gwi.parseErrorText;
else
fGwip.parseErrorText = "Error occured in InSub::transform()";
return NULL;
}
// remove outer query tables
CalpontSelectExecutionPlan::TableList tblist;
if (csep->tableList().size() >= tbCnt)
tblist.insert(tblist.begin(), csep->tableList().begin() + tbCnt, csep->tableList().end());
CalpontSelectExecutionPlan::SelectList derivedTbList;
if (csep->derivedTableList().size() >= gwi.derivedTbCnt)
derivedTbList.insert(derivedTbList.begin(),
csep->derivedTableList().begin() + gwi.derivedTbCnt,
csep->derivedTableList().end());
csep->tableList(tblist);
csep->derivedTableList(derivedTbList);
ExistsFilter* subFilter = new ExistsFilter();
subFilter->sub(csep);
if (gwi.subQuery->correlated())
subFilter->correlated(true);
else
subFilter->correlated(false);
if (fGwip.clauseType == HAVING && subFilter->correlated())
{
fGwip.fatalParseError = true;
fGwip.parseErrorText = logging::IDBErrorInfo::instance()->errorMsg(logging::ERR_NON_SUPPORT_HAVING);
}
fGwip.subselectList.push_back(csep);
return new ParseTree(subFilter);
}
void derivedTableOptimization(SCSEP& csep)
{
// @bug5634. replace the unused column with ConstantColumn from derived table column list,
// ExeMgr will not project ConstantColumn. Only count for local derived column.
// subquery may carry main query derived table list for column reference, those
// derived tables are not checked for optimization in this scope.
erydbSelectExecutionPlan::SelectList derivedTbList = csep->derivedTableList();
// @bug6156. Skip horizontal optimization for no table union.
bool horizontalOptimization = true;
for (uint i = 0; i < derivedTbList.size(); i++)
{
erydbSelectExecutionPlan *plan = dynamic_cast<erydbSelectExecutionPlan*>(derivedTbList[i].get());
erydbSelectExecutionPlan::ReturnedColumnList cols = plan->returnedCols();
vector<erydbSelectExecutionPlan::ReturnedColumnList> unionColVec;
// only do vertical optimization for union all
// @bug6134. Also skip the vertical optimization for select distinct
// because all columns need to be projected to check the distinctness.
bool verticalOptimization = false;
if (plan->distinctUnionNum() == 0 && !plan->distinct())
{
verticalOptimization = true;
for (uint j = 0; j < plan->unionVec().size(); j++)
{
unionColVec.push_back(
dynamic_cast<erydbSelectExecutionPlan*>(plan->unionVec()[j].get())->returnedCols());
}
}
if (plan->tableList().empty())
horizontalOptimization = false;
for (uint j = 0; j < plan->unionVec().size(); j++)
{
if (dynamic_cast<erydbSelectExecutionPlan*>(plan->unionVec()[j].get())->tableList().empty())
{
horizontalOptimization = false;
break;
}
}
if (verticalOptimization)
{
int64_t val = 1;
for (uint i = 0; i < cols.size(); i++)
{
//if (cols[i]->derivedTable().empty())
if (cols[i]->refCount() == 0)
{
if (cols[i]->derivedRefCol())
cols[i]->derivedRefCol()->decRefCount();
cols[i].reset(new ConstantColumn(val));
for (uint j = 0; j < unionColVec.size(); j++)
unionColVec[j][i].reset(new ConstantColumn(val));
}
}
// set back
plan->returnedCols(cols);
for (uint j = 0; j < unionColVec.size(); j++)
dynamic_cast<erydbSelectExecutionPlan*>(plan->unionVec()[j].get())->returnedCols(unionColVec[j]);
}
}
/*
* @bug5635. Move filters that only belongs to a derived table to inside the derived table.
* 1. parse tree walk to populate derivedTableFilterMap and set null candidate on the tree.
* 2. remove the null filters
* 3. and the filters of derivedTableFilterMap and append to the WHERE filter of the derived table
*
* Note:
* 1. Subquery filters is ignored because derived table can not be in subquery
* 2. While walking tree, whenever a single derive simplefilter is encountered,
* this filter is pushed to the corresponding stack
* 2. Whenever an OR operator is encountered, all the filter stack of
* that OR involving derived table are emptied and null candidate of each
* stacked filter needs to be reset (not null)
*/
ParseTree* pt = csep->filters();
map<string, ParseTree*> derivedTbFilterMap;
if (horizontalOptimization && pt)
{
pt->walk(setDerivedTable);
setDerivedFilter(pt, derivedTbFilterMap, derivedTbList);
csep->filters(pt);
}
// AND the filters of individual stack to the derived table filter tree
// @todo union filters.
// @todo outer join complication
map<string, ParseTree*>::iterator mapIt;
for (uint i = 0; i < derivedTbList.size(); i++)
{
erydbSelectExecutionPlan *plan = dynamic_cast<erydbSelectExecutionPlan*>(derivedTbList[i].get());
erydbSelectExecutionPlan::ReturnedColumnList derivedColList = plan->returnedCols();
mapIt = derivedTbFilterMap.find(plan->derivedTbAlias());
if (mapIt != derivedTbFilterMap.end())
{
// replace all derived column of this filter with real column from
// derived table projection list.
ParseTree *mainFilter = new ParseTree();
mainFilter->copyTree(*(mapIt->second));
replaceRefCol(mainFilter, derivedColList);
ParseTree* derivedFilter = plan->filters();
if (derivedFilter)
{
LogicOperator *op = new LogicOperator("and");
ParseTree *filter = new ParseTree(op);
filter->left(derivedFilter);
filter->right(mainFilter);
plan->filters(filter);
}
else
{
plan->filters(mainFilter);
}
// union filter handling
for (uint j = 0; j < plan->unionVec().size(); j++)
{
erydbSelectExecutionPlan *unionPlan =
dynamic_cast<erydbSelectExecutionPlan*>(plan->unionVec()[j].get());
erydbSelectExecutionPlan::ReturnedColumnList unionColList = unionPlan->returnedCols();
ParseTree* mainFilterForUnion = new ParseTree();
mainFilterForUnion->copyTree(*(mapIt->second));
replaceRefCol(mainFilterForUnion, unionColList);
ParseTree *unionFilter = unionPlan->filters();
if (unionFilter)
{
LogicOperator *op = new LogicOperator("and");
ParseTree *filter = new ParseTree(op);
filter->left(unionFilter);
filter->right(mainFilterForUnion);
unionPlan->filters(filter);
}
else
{
unionPlan->filters(mainFilterForUnion);
}
}
}
}
// clean derivedTbFilterMap because all the filters are copied
for( mapIt = derivedTbFilterMap.begin(); mapIt != derivedTbFilterMap.end(); ++mapIt )
delete (*mapIt).second;
// recursively process the nested derived table
for (uint i = 0; i < csep->subSelectList().size(); i++)
{
SCSEP subselect(boost::dynamic_pointer_cast<erydbSelectExecutionPlan>(csep->subSelectList()[i]));
derivedTableOptimization(subselect);
}
}