/**
* Returns merge directions between two RSs for criterias (ordering, number of reducers, reducer
* keys, partition keys). Returns null if any of categories is not mergeable.
*
* <p>Values for each index can be -1, 0, 1 1. 0 means two configuration in the category is the
* same 2. for -1, configuration of parent RS is more specific than child RS 3. for 1,
* configuration of child RS is more specific than parent RS
*/
private int[] checkStatus(ReduceSinkOperator cRS, ReduceSinkOperator pRS, int minReducer)
throws SemanticException {
ReduceSinkDesc cConf = cRS.getConf();
ReduceSinkDesc pConf = pRS.getConf();
Integer moveRSOrderTo = checkOrder(cConf.getOrder(), pConf.getOrder());
if (moveRSOrderTo == null) {
return null;
}
Integer moveReducerNumTo = checkNumReducer(cConf.getNumReducers(), pConf.getNumReducers());
if (moveReducerNumTo == null || moveReducerNumTo > 0 && cConf.getNumReducers() < minReducer) {
return null;
}
List<ExprNodeDesc> ckeys = cConf.getKeyCols();
List<ExprNodeDesc> pkeys = pConf.getKeyCols();
Integer moveKeyColTo = checkExprs(ckeys, pkeys, cRS, pRS);
if (moveKeyColTo == null) {
return null;
}
List<ExprNodeDesc> cpars = cConf.getPartitionCols();
List<ExprNodeDesc> ppars = pConf.getPartitionCols();
Integer movePartitionColTo = checkExprs(cpars, ppars, cRS, pRS);
if (movePartitionColTo == null) {
return null;
}
Integer moveNumDistKeyTo =
checkNumDistributionKey(cConf.getNumDistributionKeys(), pConf.getNumDistributionKeys());
return new int[] {
moveKeyColTo, movePartitionColTo, moveRSOrderTo, moveReducerNumTo, moveNumDistKeyTo
};
}
// for JOIN-RS case, it's not possible generally to merge if child has
// less key/partition columns than parents
protected boolean merge(ReduceSinkOperator cRS, JoinOperator pJoin, int minReducer)
throws SemanticException {
List<Operator<?>> parents = pJoin.getParentOperators();
ReduceSinkOperator[] pRSs = parents.toArray(new ReduceSinkOperator[parents.size()]);
ReduceSinkDesc cRSc = cRS.getConf();
ReduceSinkDesc pRS0c = pRSs[0].getConf();
if (cRSc.getKeyCols().size() < pRS0c.getKeyCols().size()) {
return false;
}
if (cRSc.getPartitionCols().size() != pRS0c.getPartitionCols().size()) {
return false;
}
Integer moveReducerNumTo = checkNumReducer(cRSc.getNumReducers(), pRS0c.getNumReducers());
if (moveReducerNumTo == null || moveReducerNumTo > 0 && cRSc.getNumReducers() < minReducer) {
return false;
}
Integer moveRSOrderTo = checkOrder(cRSc.getOrder(), pRS0c.getOrder());
if (moveRSOrderTo == null) {
return false;
}
boolean[] sorted = CorrelationUtilities.getSortedTags(pJoin);
int cKeySize = cRSc.getKeyCols().size();
for (int i = 0; i < cKeySize; i++) {
ExprNodeDesc cexpr = cRSc.getKeyCols().get(i);
ExprNodeDesc[] pexprs = new ExprNodeDesc[pRSs.length];
for (int tag = 0; tag < pRSs.length; tag++) {
pexprs[tag] = pRSs[tag].getConf().getKeyCols().get(i);
}
int found = CorrelationUtilities.indexOf(cexpr, pexprs, cRS, pRSs, sorted);
if (found != i) {
return false;
}
}
int cPartSize = cRSc.getPartitionCols().size();
for (int i = 0; i < cPartSize; i++) {
ExprNodeDesc cexpr = cRSc.getPartitionCols().get(i);
ExprNodeDesc[] pexprs = new ExprNodeDesc[pRSs.length];
for (int tag = 0; tag < pRSs.length; tag++) {
pexprs[tag] = pRSs[tag].getConf().getPartitionCols().get(i);
}
int found = CorrelationUtilities.indexOf(cexpr, pexprs, cRS, pRSs, sorted);
if (found != i) {
return false;
}
}
if (moveReducerNumTo > 0) {
for (ReduceSinkOperator pRS : pRSs) {
pRS.getConf().setNumReducers(cRS.getConf().getNumReducers());
}
}
return true;
}