bool operator==(const ParseTree& t1,
const ParseTree& t2)
{
if (t1.data() != NULL && t2.data() != NULL) {
if (*t1.data() != t2.data())
return false;
}
else if (t1.data() != NULL || t2.data() != NULL)
return false;
if (t1.left() != NULL && t2.left() != NULL) {
if (*t1.left() != *t2.left())
return false;
}
else if (t1.left() != NULL || t2.left() != NULL)
return false;
if (t1.right() != NULL && t2.right() != NULL) {
if (*t1.right() != *t2.right())
return false;
}
else if (t1.right() != NULL || t2.right() != NULL)
return false;
return true;
}
/**
* 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);
}
ParseTree* ObjectReader::createParseTree(messageqcpp::ByteStream& b)
{
CLASSID id = ZERO;
ParseTree* ret;
b >> (id_t&) id;
if (id == NULL_CLASS)
return NULL;
if (id != PARSETREE)
throw UnserializeException("Not a ParseTree");
ret = new ParseTree();
ret->left(createParseTree(b));
ret->right(createParseTree(b));
ret->data(createTreeNode(b));
return ret;
}
/**
* Handle MySQL's plugin functions
* This is mostly for handling the null related functions that MySQL adds to the execution plan
*/
void InSub::handleFunc(gp_walk_info* gwip, Item_func* func)
{
if (func->functype() == Item_func::TRIG_COND_FUNC || func->functype() == Item_func::COND_OR_FUNC)
{
// purpose: remove the isnull() function from the parsetree in ptWorkStack.
// IDB handles the null semantics in the join operation
// trigcond(or_cond) is the only form we recognize for now
if (func->argument_count() > 2)
{
fGwip.fatalParseError = true;
fGwip.parseErrorText = "Unsupported item in IN subquery";
return;
}
Item_cond* cond;
if (func->functype() == Item_func::TRIG_COND_FUNC)
{
Item* item;
if (func->arguments()[0]->type() == Item::REF_ITEM)
item = (Item_ref*)(func->arguments()[0])->real_item();
else
item = func->arguments()[0];
cond = (Item_cond*)(item);
}
else
{
cond = (Item_cond*)(func);
}
if (cond->functype() == Item_func::COND_OR_FUNC)
{
// (cache=item) case. do nothing. ignore trigcond()?
if (cond->argument_list()->elements == 1)
return;
// (cache=item or isnull(item)) case. remove "or isnull()"
if (cond->argument_list()->elements == 2)
{
// don't know how to deal with this. don't think it's a fatal error either.
if (gwip->ptWorkStack.empty())
return;
ParseTree* pt = gwip->ptWorkStack.top();
if (!pt->left() || !pt->right())
return;
SimpleFilter* sf = dynamic_cast<SimpleFilter*>(pt->left()->data());
//assert (sf && sf->op()->op() == execplan::OP_ISNULL);
if (!sf || sf->op()->op() != execplan::OP_ISNULL)
return;
delete sf;
sf = dynamic_cast<SimpleFilter*>(pt->right()->data());
//idbassert(sf && sf->op()->op() == execplan::OP_EQ);
if (!sf || sf->op()->op() != execplan::OP_EQ)
return;
// set NULLMATCH for both operand. It's really a setting for the join.
// should only set NULLMATCH when the subtype is NOT_IN. for some IN subquery
// with aggregation column, MySQL inefficiently convert to:
// (cache=item or item is null) and item is not null, which is equivalent to
// cache = item. Do not set NULLMATCH for this case.
// Because we don't know IN or NOTIN yet, set candidate bit and switch to NULLMATCH
// later in handleNot function.
if (sf->lhs()->joinInfo() & JOIN_CORRELATED)
sf->lhs()->joinInfo(sf->lhs()->joinInfo() | JOIN_NULLMATCH_CANDIDATE);
if (sf->rhs()->joinInfo() & JOIN_CORRELATED)
sf->rhs()->joinInfo(sf->rhs()->joinInfo() | JOIN_NULLMATCH_CANDIDATE);
pt = pt->right();
gwip->ptWorkStack.pop();
gwip->ptWorkStack.push(pt);
}
}
else if (cond->functype() == Item_func::EQ_FUNC)
{
// not in (select const ...)
if (gwip->ptWorkStack.empty())
return;
ParseTree* pt = gwip->ptWorkStack.top();
SimpleFilter* sf = dynamic_cast<SimpleFilter*>(pt->data());
if (!sf || sf->op()->op() != execplan::OP_EQ)
return;
if (sf->lhs()->joinInfo() & JOIN_CORRELATED)
sf->lhs()->joinInfo(sf->lhs()->joinInfo() | JOIN_NULLMATCH_CANDIDATE);
if (sf->rhs()->joinInfo() & JOIN_CORRELATED)
sf->rhs()->joinInfo(sf->rhs()->joinInfo() | JOIN_NULLMATCH_CANDIDATE);
}
}
}
