Status Operators::Join(const string& result, // Name of the output relation
const int projCnt, // Number of attributes in the projection
const attrInfo projNames[], // List of projection attributes
const attrInfo* attr1, // Left attr in the join predicate
const Operator op, // Predicate operator
const attrInfo* attr2) // Right attr in the join predicate
{
/* Your solution goes here */
Status prep_status;
int rec_len = 0;
AttrDesc output_attrs[projCnt];
for (int i = 0; i < projCnt; i++) {
prep_status = attrCat->getInfo(projNames[i].relName, projNames[i].attrName, output_attrs[i]);
if (prep_status != OK) {
return prep_status;
}
rec_len += output_attrs[i].attrLen;
}
AttrDesc attrdesc1, attrdesc2;
prep_status = attrCat->getInfo(attr1->relName, attr1->attrName, attrdesc1);
if (prep_status != OK) {
return prep_status;
}
prep_status = attrCat->getInfo(attr2->relName, attr2->attrName, attrdesc2);
if (prep_status != OK) {
return prep_status;
}
Status status;
if (op != EQ) { // non-equi join
status = SNL(result, projCnt, output_attrs, attrdesc1, op, attrdesc2, rec_len);
}
else {
if (attrdesc1.indexed) {
status = INL(result, projCnt, output_attrs, attrdesc2, op, attrdesc1, rec_len);
}
else if (attrdesc2.indexed) {
status = INL(result, projCnt, output_attrs, attrdesc1, op, attrdesc2, rec_len);
}
else {
status = SMJ(result, projCnt, output_attrs, attrdesc1, op, attrdesc2, rec_len);
}
}
if (status != OK) {
return status;
}
return OK;
}
Status Operators::Join(const string& result, // Name of the output relation
const int projCnt, // Number of attributes in the projection
const attrInfo projNames[], // List of projection attributes
const attrInfo* attr1, // Left attr in the join predicate
const Operator op, // Predicate operator
const attrInfo* attr2) // Right attr in the join predicate
{
Status status;
/* Minirel guarantees there will be a Join Condition => Populate the attr_desc objects */
AttrDesc attr_desc1, attr_desc2;
status = attrCat->getInfo(attr1->relName, attr1->attrName, attr_desc1);
if(status != OK) return status;
status = attrCat->getInfo(attr2->relName, attr2->attrName, attr_desc2);
if(status != OK) return status;
/* Find the length of a resulting record and populate the proj_names array */
int reclen;
AttrDesc *proj_names = new AttrDesc[projCnt];
status = ConvertInfoToDesc(projNames, projCnt, proj_names, reclen);
if(status != OK) {
delete [] proj_names;
return status;
}
if(op != EQ)
SNL(result, projCnt, proj_names, attr_desc1, op, attr_desc2, reclen);
else {
if(attr_desc1.indexed)
INL(result, projCnt, proj_names, attr_desc2, negate_operator(op), attr_desc1, reclen);
else if(attr_desc1.indexed)
INL(result, projCnt, proj_names, attr_desc1, op, attr_desc2, reclen);
else
SMJ(result, projCnt, proj_names, attr_desc1, op, attr_desc2, reclen);
}
return OK;
}
Status Operators::Join(const string& result, // Name of the output relation
const int projCnt, // Number of attributes in the projection
const attrInfo projNames[], // List of projection attributes
const attrInfo* attr1, // Left attr in the join predicate
const Operator op, // Predicate operator
const attrInfo* attr2) // Right attr in the join predicate
{
// Fetch attribute descriptions
string relation1 = attr1->relName;
string relation2 = attr2->relName;
AttrDesc* inputDescs1, * inputDescs2;
int attrCnt1, attrCnt2;
Status status = attrCat->getRelInfo(relation1, attrCnt1, inputDescs1);
if (status != OK) {
return status;
}
status = attrCat->getRelInfo(relation2, attrCnt2, inputDescs2);
if (status != OK) {
return status;
}
// Construct list of projected attribute descriptions
AttrDesc* projAttrDescs = new AttrDesc[projCnt];
int reclen = 0;
//search through the first relation for an attribute match
for (int i = 0; i < projCnt; ++i) {
bool found = false;
int j;
for (j = 0; j < attrCnt1; ++j) {
if (!strcmp(projNames[i].attrName, inputDescs1->attrName) &&
!strcmp(projNames[i].relName, inputDescs1->relName)) {
*projAttrDescs++ = *inputDescs1;
reclen += inputDescs1->attrLen;
found = true;
break;
}
inputDescs1++;
}
inputDescs1 -= j;
if (found) {
continue;
}
//If not found in the first relation, search for the attribute in the second relation
for (j = 0; j < attrCnt2; ++j) {
if (!strcmp(projNames[i].attrName, inputDescs2->attrName) &&
!strcmp(projNames[i].relName, inputDescs2->relName)) {
*projAttrDescs++ = *inputDescs2;
reclen += inputDescs2->attrLen;
found = true;
break;
}
inputDescs2++;
}
inputDescs2 -= j;
assert(found);
}
projAttrDescs -= projCnt;
// Convert criterion attributes to AttrDesc
AttrDesc cDesc1, cDesc2;
status = attrCat->getInfo(relation1, attr1->attrName, cDesc1);
if (status != OK) {
return status;
}
status = attrCat->getInfo(relation2, attr2->attrName, cDesc2);
if (status != OK) {
return status;
}
// Delegate sub-join operations
if (op != EQ) {
//Perform SNL. Might have to switch relation 1 and relation2
//based on which is more efficient as the outer relation
HeapFileScan hfs1(relation1, status);
if(status != OK)
{ return status;
}
HeapFileScan hfs2(relation2, status);
if(status != OK)
{ return status;
}
//Get num tuples for each file
int numTuples1 = hfs1.getRecCnt();
int numTuples2 = hfs2.getRecCnt();
int relSize1 = 0, relSize2 = 0;
for (int i = 0; i < attrCnt1; ++i) {
relSize1 += (inputDescs1 + i)->attrLen;
}
for (int i = 0; i < attrCnt1; ++i) {
relSize2 += (inputDescs2 + i)->attrLen;
}
//Calculate num pages for each file
int relPages1 = ceil((numTuples1*relSize1)*1.0/PAGESIZE);
int relPages2 = ceil((numTuples2*relSize2)*1.0/PAGESIZE);
//Use formula to calculate total IOs, to decide in which order to send
//SNL the two AttrDesc structs (first parameter is outer, second is inner)
if(relPages1 + numTuples1*relPages2 <= relPages2 + numTuples2*relPages1) {
return SNL(
result,
projCnt,
projAttrDescs,
cDesc1,
op,
cDesc2,
reclen);
} else {
//Operator needs to be flipped if the order is switched
Operator op2;
switch(op)
{
case LT: op2 = GT; break;
case GT: op2 = LT; break;
case LTE: op2 = GTE; break;
case GTE: op2 = LTE; break;
default: break;
}
return SNL(
result,
projCnt,
projAttrDescs,
cDesc2,
op2,
cDesc1,
reclen);
}
}
if (cDesc1.indexed || cDesc2.indexed) {
return INL(
result,
projCnt,
projAttrDescs,
cDesc1,
op,
cDesc2,
reclen);
}
return SMJ(
result,
projCnt,
projAttrDescs,
cDesc1,
op,
cDesc2,
reclen);
}
