Hello All,

I found some code online to help me create a custom Rollup-Summary solution. It works great in Sandbox. But the system says that one of the queries is non-selective (at least when I did a big delete event).

How is it non-selective? The WHERE clause is based upon a lookup field (which is about as specific an index as possible).

Here is the code:
 

public class RollUpSummaryUtility {
    //the following class will be used to house the field names
    //and desired operations
    public class fieldDefinition {
        public String operation {get;set;}
        public String childField {get;set;}
        public String parentField {get;set;}
        public fieldDefinition (String o, String c, String p) {
            operation = o;
            childField = c;
            parentField = p;
        }
    }
    public static void rollUpTrigger(list<fieldDefinition> fieldDefinitions,
                                     list<sObject> records, String childObject, String childParentLookupField,
                                     String parentObject, String queryFilter) {
                                         //Limit the size of list by using Sets which do not contain duplicate
                                         //elements prevents hitting governor limits
                                         set<Id> parentIds = new set<Id>();
                                         for(sObject s : records) {
                                             parentIds.add((Id)s.get(childParentLookupField));
                                         }
                                         //populate query text strings to be used in child aggregrator and
                                         //parent value assignment
                                         String fieldsToAggregate = '';
                                         String parentFields = '';
                                         for(fieldDefinition d : fieldDefinitions) {
                                             fieldsToAggregate += d.operation + '(' + d.childField + ') ' +
                                                 ', ';
                                             parentFields += d.parentField + ', ';
                                         }
                                         //Using dynamic SOQL with aggergate results to populate parentValueMap
                                         String aggregateQuery = 'Select ' + fieldsToAggregate +
                                             childParentLookupField + ' from ' + childObject + ' where ' +
                                             childParentLookupField + ' IN :parentIds ' + queryFilter + ' ' +
                                             ' group by ' + childParentLookupField;
                                         //Map will contain one parent record Id per one aggregate object
                                         map<Id, AggregateResult> parentValueMap =
                                             new map <Id, AggregateResult>();
                                         for(AggregateResult q : Database.query(aggregateQuery)){
                                             parentValueMap.put((Id)q.get(childParentLookupField), q);
                                         }
                                         //list of parent object records to update
                                         list<sObject> parentsToUpdate = new list<sObject>();
                                         String parentQuery = 'select ' + parentFields + ' Id ' +
                                             ' from ' + parentObject + ' where Id IN :parentIds';
                                         //for each affected parent object, retrieve aggregate results and
                                         //for each field definition add aggregate value to parent field
                                         for(sObject s : Database.query(parentQuery)) {
                                             Integer row = 0; //row counter reset for every parent record
                                             for(fieldDefinition d : fieldDefinitions) {
                                                 String field = 'expr' + row.format();
                                                 AggregateResult r = parentValueMap.get(s.Id);
                                                 //r will be null if no records exist
                                                 //(e.g. last record deleted)
                                                 if(r != null) {
                                                     Decimal value = ((Decimal)r.get(field) == null ) ? 0 :
                                                     (Decimal)r.get(field);
                                                     s.put(d.parentField, value);
                                                 } else {
                                                     s.put(d.parentField, 0);
                                                 }
                                                 row += 1; //plus 1 for every field definition after first
                                             }
                                             parentsToUpdate.add(s);
                                         }
                                         //if parent records exist, perform update of all parent records
                                         //with a single DML statement
                                         if(parentsToUpdate.Size() > 0) {
                                             update parentsToUpdate;
                                         }
                                     }
}

Can somebody tell me what I am missing?