/**
* This function initializes the data structures for an operator. This over-rides the
* corresponding function in the base class.
*
* @return True if the operator is to continue and false otherwise
*/
protected void opInitialize() {
// Get the grouping attributes
skolem grouping = logicalGroupOperator.getSkolemAttributes();
Vector groupVars = grouping.getVarList();
hasher = new Hasher(groupVars);
groupAttrs = new int[groupVars.size()];
for (int i = 0; i < groupAttrs.length; i++) {
groupAttrs[i] = inputTupleSchemas[0].getPosition(((Attribute) groupVars.get(i)).getName());
}
hasher.resolveVariables(inputTupleSchemas[0]);
// Initialize the hash tables
hash2final = new HashMap();
hash2partial = new HashMap();
hash2tuple = new HashMap();
}
