// we want BiRelat to be cacheable
NABoolean BiRelat::isCacheableExpr(CacheWA& cwa)
{
if (cwa.getPhase() >= CmpMain::BIND && getArity() == 2) {
if (getOperatorType() == ITM_EQUAL) {
ItemExpr *leftC=child(0), *rightC=child(1);
OperatorTypeEnum leftO = leftC->getOperatorType();
OperatorTypeEnum rightO = rightC->getOperatorType();
BaseColumn *base;
if (leftO == ITM_BASECOLUMN) {
base = (BaseColumn*)leftC;
if (base->isKeyColumnValue(*rightC)) {
cwa.addToUsedKeys(base);
}
return TRUE;
}
else if (rightO == ITM_BASECOLUMN) {
base = (BaseColumn*)rightC;
if (base->isKeyColumnValue(*leftC)) {
cwa.addToUsedKeys(base);
}
return TRUE;
}
else if (leftO == ITM_ITEM_LIST && rightO == ITM_ITEM_LIST &&
((ItemList*)leftC)->isListOfCacheableSelPred
(cwa, (ItemList*)rightC)) {
return TRUE;
}
else {
// we want all other equality comparisons to be cacheable, eg,
// retail_div_cd||acct_type_cd||substring(acct_id,1,8)='20V43085193'
return TRUE;
}
}
else {
return TRUE;
// other binary comparison predicates can be cacheable, but are
// not necessarily parameterizable, see BiRelat::normalizeForCache
}
}
return FALSE;
}
// does this query's selection predicate list qualify query
// to be cacheable after this phase?
NABoolean ItemList::isListOfCacheableSelPred
(CacheWA& cwa, ItemList *other) const
{
Int32 arity = getArity();
NABoolean result = FALSE;
if (cwa.getPhase() >= CmpMain::BIND &&
other && arity == other->getArity()) {
// assume this is an AND list, so, we need only one
// cacheable conjunct to consider the list cacheable.
for (Int32 x = 0; x < arity; x++) {
ItemExpr *leftC = child(x), *rightC = other->child(x);
OperatorTypeEnum leftO = leftC->getOperatorType();
OperatorTypeEnum rightO = rightC->getOperatorType();
BaseColumn *base;
if (leftO == ITM_BASECOLUMN) {
base = (BaseColumn*)leftC;
if (base->isKeyColumnValue(*rightC)) {
cwa.addToUsedKeys(base);
}
result = TRUE;
continue;
}
else if (rightO == ITM_BASECOLUMN) {
base = (BaseColumn*)rightC;
if (base->isKeyColumnValue(*leftC)) {
cwa.addToUsedKeys(base);
}
result = TRUE;
continue;
}
else if (leftO == ITM_ITEM_LIST && rightO == ITM_ITEM_LIST &&
((ItemList*)leftC)->isListOfCacheableSelPred
(cwa, (ItemList*)rightC)) {
result = TRUE;
continue;
}
}
}
return result;
}
