Lng32 ComTdbSendTop::minSendBufferSize(Lng32 downRecLen, Lng32 numRecs)
{
// start with the regular size it would take to pack the records
// into an SqlBuffer
#pragma nowarn(1506) // warning elimination
Lng32 recSpace = SqlBufferNeededSize(numRecs, downRecLen);
#pragma warn(1506) // warning elimination
// now add the needed space for the ExpControlInfo struct that goes
// along with each record
#pragma nowarn(1506) // warning elimination
Lng32 delta = SqlBufferNeededSize(2, sizeof(ControlInfo)) -
SqlBufferNeededSize(1, sizeof(ControlInfo));
#pragma warn(1506) // warning elimination
return recSpace + numRecs * delta;
}
short MergeUnion::codeGen(Generator * generator)
{
ExpGenerator * exp_gen = generator->getExpGenerator();
Space * space = generator->getSpace();
MapTable * my_map_table = generator->appendAtEnd();
////////////////////////////////////////////////////////////////////////////
//
// Layout at this node:
//
// |------------------------------------------------------------------------|
// | input data | Unioned data | left child's data | right child's data |
// | ( I tupps ) | ( 1 tupp ) | ( L tupps ) | ( R tupp ) |
// |------------------------------------------------------------------------|
// <-- returned row to parent --->
// <------------ returned row from left child ------->
// <-------------------- returned row from right child --------------------->
//
// input data: the atp input to this node by its parent.
// unioned data: tupp where the unioned result is moved
// left child data: tupps appended by the left child
// right child data: tupps appended by right child
//
// Input to left child: I + 1 tupps
// Input to right child: I + 1 + L tupps
//
// Tupps returned from left and right child are only used to create the
// unioned data. They are not returned to parent.
//
////////////////////////////////////////////////////////////////////////////
ex_cri_desc * given_desc
= generator->getCriDesc(Generator::DOWN);
ex_cri_desc * returned_desc = NULL;
if(child(0) || child(1))
returned_desc = new(space) ex_cri_desc(given_desc->noTuples() + 1, space);
else
returned_desc = given_desc;
// expressions to move the left and right child's output to the
// unioned row.
ex_expr * left_expr = 0;
ex_expr * right_expr = 0;
// expression to compare left and right child's output to
// evaluate merge union.
ex_expr * merge_expr = 0;
// Expression to conditionally execute the left or right child.
ex_expr *cond_expr = NULL;
// Expression to handle triggered action excpetion
ex_expr *trig_expr = NULL;
// It is OK for neither child to exist when generating a merge union TDB
// for index maintenenace. The children are filled in at build time.
//
GenAssert((child(0) AND child(1)) OR (NOT child(0) AND NOT (child(1))),
"MergeUnion -- missing one child");
ComTdb * left_child_tdb = NULL;
ComTdb * right_child_tdb = NULL;
ExplainTuple *leftExplainTuple = NULL;
ExplainTuple *rightExplainTuple = NULL;
NABoolean afterUpdate = FALSE;
NABoolean rowsFromLeft = TRUE;
NABoolean rowsFromRight = TRUE;
if(child(0) && child(1)) {
// if an update operation is found before the execution of the
// IF statement, set afterUpdate to 1 indicating that an update operation
// was performed before the execution of the IF statement. Which
// is used at runtime to decide whether to set rollbackTransaction in the
// diagsArea
if (generator->updateWithinCS() && getUnionForIF()) {
afterUpdate = TRUE;
}
// generate the left child
generator->setCriDesc(returned_desc, Generator::DOWN);
child(0)->codeGen(generator);
left_child_tdb = (ComTdb *)(generator->getGenObj());
leftExplainTuple = generator->getExplainTuple();
// MVs --
// If the left child does not have any outputs, don't expect any rows.
if (child(0)->getGroupAttr()->getCharacteristicOutputs().isEmpty())
rowsFromLeft = FALSE;
// if an update operation is found in the left subtree of this Union then
// set rowsFromLeft to 0 which is passed on to execution tree indicating
// that this Union node is not expecting rows from the left child, then
// foundAnUpdate_ is reset so it can be reused while doing codGen() on
// the right sub tree
if (getUnionForIF()) {
if (! getCondEmptyIfThen()) {
if (generator->foundAnUpdate()) {
rowsFromLeft = FALSE;
generator->setFoundAnUpdate(FALSE);
}
}
else {
rowsFromLeft = FALSE;
}
}
// descriptor returned by left child is given to right child as input.
generator->setCriDesc(generator->getCriDesc(Generator::UP),
Generator::DOWN);
child(1)->codeGen(generator);
right_child_tdb = (ComTdb *)(generator->getGenObj());
rightExplainTuple = generator->getExplainTuple();
// MVs
// If the right child does not have any outputs, don't expect any rows.
if (child(1)->getGroupAttr()->getCharacteristicOutputs().isEmpty())
rowsFromRight = FALSE;
// if an update operation is found in the right subtree of this CS then
// set rowsFromRight to 0 which is passed on to execution tree indicating
// that this CS node is not expecting rows from the right child, then
// foundAnUpdate_ is reset so it can be reused while doing codGen() on
// the left or right child of another CS node
if (getUnionForIF()) {
if (! getCondEmptyIfElse()) {
if (generator->foundAnUpdate()) {
rowsFromRight = FALSE;
}
}
else {
rowsFromRight = FALSE;
}
// we cannot always expect a row from a conditional operator. If it is an
// IF statement without an ELSE and the condition fails then we do not get
// any rows back. So we allow a conditional union operator to handle all
// errors below it and for the purposes of 8015 error / 8014 warning
// treat it as an update node. In this way the nodes above it do not expect
// any row from this child and do not raise an error if no row is returned.
// 8014/8015 type errors within this IF statement are handled as in any
// regular CS.
generator->setFoundAnUpdate(TRUE);
}
}
// Create the unioned row.
// colMapTable() is a list of ValueIdUnion nodes where each node points to
// the corresponding left and the right output entries.
// Generate expressions to move the left and right child's output to
// the unioned row.
ValueIdList left_val_id_list;
ValueIdList right_val_id_list;
CollIndex i;
for (i = 0; i < colMapTable().entries(); i++)
{
ValueIdUnion * vidu_node = (ValueIdUnion *)(((colMapTable()[i]).getValueDesc())->getItemExpr());
Cast * cnode;
if (vidu_node->getResult().getType().getTypeQualifier() != NA_ROWSET_TYPE) {
// move left child's output to result. The 'type' of Cast result is same
// as that of the vidu_node.
cnode = new(generator->wHeap())
Cast(((vidu_node->getLeftSource()).getValueDesc())->getItemExpr(),
&(vidu_node->getResult().getType()));
}
else {
// We indicate that the whole array is to be copied
SQLRowset *rowsetInfo = (SQLRowset *) &(vidu_node->getResult().getType());
SQLRowset *newRowset = new (generator->wHeap())
SQLRowset(generator->wHeap(), rowsetInfo->getElementType(),
rowsetInfo->getMaxNumElements(),
rowsetInfo->getNumElements());
newRowset->useTotalSize() = TRUE;
cnode = new(generator->wHeap())
Cast(((vidu_node->getLeftSource()).getValueDesc())->getItemExpr(),
newRowset);
}
cnode->bindNode(generator->getBindWA());
left_val_id_list.insert(cnode->getValueId());
if (vidu_node->getResult().getType().getTypeQualifier() != NA_ROWSET_TYPE) {
// move left child's output to result. The 'type' of Cast result is same
// as that of the vidu_node.
cnode = new(generator->wHeap())
Cast(((vidu_node->getRightSource()).getValueDesc())->getItemExpr(),
&(vidu_node->getResult().getType()));
}
else {
// We indicate that the whole array is to be copied
SQLRowset *rowsetInfo = (SQLRowset *) &(vidu_node->getResult().getType());
SQLRowset *newRowset = new (generator->wHeap())
SQLRowset(generator->wHeap(), rowsetInfo->getElementType(),
rowsetInfo->getMaxNumElements(),
rowsetInfo->getNumElements());
newRowset->useTotalSize() = TRUE;
cnode = new(generator->wHeap())
Cast(((vidu_node->getRightSource()).getValueDesc())->getItemExpr(),
newRowset);
}
cnode->bindNode(generator->getBindWA());
right_val_id_list.insert(cnode->getValueId());
}
ExpTupleDesc * tuple_desc = 0;
ULng32 tuple_length = 0;
if(child(0) && child(1)) {
exp_gen->generateContiguousMoveExpr(left_val_id_list,
0, // don't add convert nodes
1, returned_desc->noTuples() - 1,
ExpTupleDesc::SQLARK_EXPLODED_FORMAT,
tuple_length,
&left_expr,
&tuple_desc,
ExpTupleDesc::SHORT_FORMAT);
exp_gen->generateContiguousMoveExpr(right_val_id_list,
0, // don't add convert nodes
1, returned_desc->noTuples() - 1,
ExpTupleDesc::SQLARK_EXPLODED_FORMAT,
tuple_length,
&right_expr);
}
// add value ids for all vidu_nodes to my map table. This is the
// the map table that will be returned. The attributes of the value ids
// are same as that of left(or right) expression outputs.
for (i = 0; i < colMapTable().entries(); i++)
{
ValueIdUnion * vidu_node = (ValueIdUnion *)(((colMapTable()[i]).getValueDesc())->getItemExpr());
Attributes * attr =
generator->addMapInfoToThis(my_map_table, vidu_node->getValueId(),
generator->getMapInfo(left_val_id_list[i])->getAttr())->getAttr();
attr->setAtp(0);
}
// describe the returned unioned row
returned_desc->setTupleDescriptor(returned_desc->noTuples() - 1, tuple_desc);
// if sort-merge union is being done, generate expression to
// compare the left and the right values.
// This predicate should return TRUE if the left value is
// less than the right value.
merge_expr = 0;
if (getMergeExpr()) {
// generate the merge predicate.
ItemExpr * mergeExpr = new(generator->wHeap()) BoolResult(getMergeExpr());
mergeExpr->bindNode(generator->getBindWA());
exp_gen->generateExpr(mergeExpr->getValueId(),
ex_expr::exp_SCAN_PRED,
&merge_expr);
}
// If conditional union, generate conditional expression, and ignore
// right child if it was just being used as a no-op.
cond_expr = 0;
if (NOT condExpr().isEmpty()) {
ItemExpr *condExp = condExpr().rebuildExprTree(ITM_AND, TRUE, TRUE);
exp_gen->generateExpr(condExp->getValueId(),
ex_expr::exp_SCAN_PRED,
&cond_expr);
}
// If conditional union, generate triggered action exception error
if (NOT trigExceptExpr().isEmpty()) {
ItemExpr *trigExp = trigExceptExpr().rebuildExprTree(ITM_AND, TRUE, TRUE);
exp_gen->generateExpr(trigExp->getValueId(),
ex_expr::exp_SCAN_PRED,
&trig_expr);
}
// remove both children's map table. Nothing from child's context
// should be visible from here on upwards.
generator->removeAll(my_map_table);
// Ensure the default buffer size is at least as large as the unioned output
// row.
UInt32 outputBuffSize = MAXOF( getDefault(GEN_UN_BUFFER_SIZE),
tuple_length );
outputBuffSize = SqlBufferNeededSize( 1, // # of tuples
outputBuffSize,
SqlBuffer::NORMAL_
);
ComTdbUnion * union_tdb
= new(space) ComTdbUnion(
left_child_tdb,
right_child_tdb,
left_expr,
right_expr,
merge_expr,
cond_expr,
trig_expr,
tuple_length, // unioned rowlen
returned_desc->noTuples()-1, // tupp index for
// unioned buffer
given_desc,
returned_desc,
(queue_index)getDefault(GEN_UN_SIZE_DOWN),
(queue_index)getDefault(GEN_UN_SIZE_UP),
(Cardinality) (getInputCardinality() * getEstRowsUsed()).getValue(),
getDefault(GEN_UN_NUM_BUFFERS),
outputBuffSize,
getOrderedUnion(),
getBlockedUnion(), //++ Triggers -
hasNoOutputs(), //++ Triggers -
rowsFromLeft,
rowsFromRight,
afterUpdate,
getInNotAtomicStatement());
generator->initTdbFields(union_tdb);
// If it does not have two children, this is index maintenance code and
// should not be Explained
if (!generator->explainDisabled()) {
generator->setExplainTuple(addExplainInfo(union_tdb,
leftExplainTuple,
rightExplainTuple,
generator));
}
// restore the original down cri desc since this node changed it.
generator->setCriDesc(given_desc, Generator::DOWN);
// set the new up cri desc.
generator->setCriDesc(returned_desc, Generator::UP);
generator->setGenObj(this, union_tdb);
return 0;
}