Ejemplo n.º 1
0
 /**
  * Add a value to this aggregate.
  *
  * @param database the database
  * @param distinct if the calculation should be distinct
  * @param v the value
  */
 void add(Database database, boolean distinct, Value v) {
   if (aggregateType == Aggregate.SELECTIVITY) {
     count++;
     if (distinctHashes == null) {
       distinctHashes = new IntIntHashMap();
     }
     int size = distinctHashes.size();
     if (size > Constants.SELECTIVITY_DISTINCT_COUNT) {
       distinctHashes = new IntIntHashMap();
       m2 += size;
     }
     int hash = v.hashCode();
     // the value -1 is not supported
     distinctHashes.put(hash, 1);
     return;
   } else if (aggregateType == Aggregate.COUNT_ALL) {
     count++;
     return;
   } else if (aggregateType == Aggregate.HISTOGRAM) {
     if (distinctValues == null) {
       distinctValues = ValueHashMap.newInstance();
     }
     AggregateData a = distinctValues.get(v);
     if (a == null) {
       if (distinctValues.size() < Constants.SELECTIVITY_DISTINCT_COUNT) {
         a = new AggregateData(Aggregate.HISTOGRAM, dataType);
         distinctValues.put(v, a);
       }
     }
     if (a != null) {
       a.count++;
     }
     return;
   }
   if (v == ValueNull.INSTANCE) {
     return;
   }
   count++;
   if (distinct) {
     if (distinctValues == null) {
       distinctValues = ValueHashMap.newInstance();
     }
     distinctValues.put(v, this);
     return;
   }
   switch (aggregateType) {
     case Aggregate.COUNT:
     case Aggregate.HISTOGRAM:
       return;
     case Aggregate.SUM:
       if (value == null) {
         value = v.convertTo(dataType);
       } else {
         v = v.convertTo(value.getType());
         value = value.add(v);
       }
       break;
     case Aggregate.AVG:
       if (value == null) {
         value = v.convertTo(DataType.getAddProofType(dataType));
       } else {
         v = v.convertTo(value.getType());
         value = value.add(v);
       }
       break;
     case Aggregate.MIN:
       if (value == null || database.compare(v, value) < 0) {
         value = v;
       }
       break;
     case Aggregate.MAX:
       if (value == null || database.compare(v, value) > 0) {
         value = v;
       }
       break;
     case Aggregate.GROUP_CONCAT:
       {
         if (list == null) {
           list = New.arrayList();
         }
         list.add(v);
         break;
       }
     case Aggregate.STDDEV_POP:
     case Aggregate.STDDEV_SAMP:
     case Aggregate.VAR_POP:
     case Aggregate.VAR_SAMP:
       {
         // Using Welford's method, see also
         // http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
         // http://www.johndcook.com/standard_deviation.html
         double x = v.getDouble();
         if (count == 1) {
           mean = x;
           m2 = 0;
         } else {
           double delta = x - mean;
           mean += delta / count;
           m2 += delta * (x - mean);
         }
         break;
       }
     case Aggregate.BOOL_AND:
       v = v.convertTo(Value.BOOLEAN);
       if (value == null) {
         value = v;
       } else {
         value =
             ValueBoolean.get(value.getBoolean().booleanValue() && v.getBoolean().booleanValue());
       }
       break;
     case Aggregate.BOOL_OR:
       v = v.convertTo(Value.BOOLEAN);
       if (value == null) {
         value = v;
       } else {
         value =
             ValueBoolean.get(value.getBoolean().booleanValue() || v.getBoolean().booleanValue());
       }
       break;
     default:
       DbException.throwInternalError("type=" + aggregateType);
   }
 }
Ejemplo n.º 2
0
 void merge(Database database, boolean distinct, Value v) {
   if (aggregateType == Aggregate.COUNT || aggregateType == Aggregate.COUNT_ALL) {
     count += v.getLong();
     return;
   } else if (aggregateType == Aggregate.HISTOGRAM) {
     if (distinctValues == null) {
       distinctValues = ValueHashMap.newInstance();
     }
     AggregateData a = distinctValues.get(v);
     if (a == null) {
       if (distinctValues.size() < Constants.SELECTIVITY_DISTINCT_COUNT) {
         a = new AggregateData(Aggregate.HISTOGRAM, dataType);
         distinctValues.put(v, a);
       }
     }
     if (a != null) {
       a.count++;
     }
     return;
   }
   if (v == ValueNull.INSTANCE) {
     return;
   }
   count++;
   if (distinct) {
     if (distinctValues == null) {
       distinctValues = ValueHashMap.newInstance();
     }
     distinctValues.put(v, this);
     return;
   }
   switch (aggregateType) {
     case Aggregate.COUNT:
     case Aggregate.HISTOGRAM:
       return;
     case Aggregate.SUM:
     case Aggregate.SELECTIVITY:
       if (value == null) {
         value = v.convertTo(dataType);
       } else {
         v = v.convertTo(value.getType());
         value = value.add(v);
       }
       break;
     case Aggregate.AVG:
       if (value == null) {
         value = v.convertTo(DataType.getAddProofType(dataType));
       } else {
         // AVG聚合函数merge的次数不会超过1
         DbException.throwInternalError("type=" + aggregateType);
       }
       break;
     case Aggregate.MIN:
       if (value == null || database.compare(v, value) < 0) {
         value = v;
       }
       break;
     case Aggregate.MAX:
       if (value == null || database.compare(v, value) > 0) {
         value = v;
       }
       break;
     case Aggregate.GROUP_CONCAT:
       {
         if (list == null) {
           list = New.arrayList();
         }
         list.add(v);
         break;
       }
     case Aggregate.STDDEV_POP:
     case Aggregate.STDDEV_SAMP:
     case Aggregate.VAR_POP:
     case Aggregate.VAR_SAMP:
       {
         v = v.convertTo(Value.DOUBLE);
         if (value == null) {
           value = v;
         } else {
           // 这4种聚合函数merge的次数不会超过1
           DbException.throwInternalError("type=" + aggregateType);
         }
         break;
       }
     case Aggregate.BOOL_AND:
       v = v.convertTo(Value.BOOLEAN);
       if (value == null) {
         value = v;
       } else {
         value =
             ValueBoolean.get(value.getBoolean().booleanValue() && v.getBoolean().booleanValue());
       }
       break;
     case Aggregate.BOOL_OR:
       v = v.convertTo(Value.BOOLEAN);
       if (value == null) {
         value = v;
       } else {
         value =
             ValueBoolean.get(value.getBoolean().booleanValue() || v.getBoolean().booleanValue());
       }
       break;
     default:
       DbException.throwInternalError("type=" + aggregateType);
   }
 }