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1
5 package org.h2.expression;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Constants;
10 import org.h2.engine.Database;
11 import org.h2.message.Message;
12 import org.h2.util.ObjectArray;
13 import org.h2.util.ValueHashMap;
14 import org.h2.value.Value;
15 import org.h2.value.ValueBoolean;
16 import org.h2.value.ValueDouble;
17 import org.h2.value.ValueInt;
18 import org.h2.value.ValueNull;
19
20 public class AggregateData {
21 private int aggregateType;
22 private int count;
23 private ValueHashMap distinctValues;
24 private Value value;
25 private double sum, vpn;
26 private ObjectArray list;
27
28 AggregateData(int aggregateType) {
29 this.aggregateType = aggregateType;
30 }
31
32 void add(Database database, boolean distinct, Value v) throws SQLException {
33 if(aggregateType == Aggregate.SELECTIVITY) {
34 count++;
35 if(distinctValues == null) {
36 distinctValues = new ValueHashMap(database);
37 }
38 int size = distinctValues.size();
39 if(size > Constants.SELECTIVITY_DISTINCT_COUNT) {
40 distinctValues = new ValueHashMap(database);
41 sum += size;
42 }
43 distinctValues.put(v, this);
44 return;
45 }
46 if(aggregateType == Aggregate.COUNT_ALL) {
47 count++;
48 return;
49 }
50 if(v == ValueNull.INSTANCE) {
51 return;
52 }
53 count++;
54 if(distinct) {
55 if(distinctValues == null) {
56 distinctValues = new ValueHashMap(database);
57 }
58 distinctValues.put(v, this);
59 return;
60 }
61 switch(aggregateType) {
62 case Aggregate.COUNT:
63 return;
64 case Aggregate.SUM:
65 case Aggregate.AVG:
66 if(value == null) {
67 value = v;
68 } else {
69 value = value.add(v);
70 }
71 break;
72 case Aggregate.MIN:
73 if(value == null || database.compare(v, value) < 0) {
74 value = v;
75 }
76 break;
77 case Aggregate.MAX:
78 if(value == null || database.compare(v, value) > 0) {
79 value = v;
80 }
81 break;
82 case Aggregate.GROUP_CONCAT: {
83 if(list == null) {
84 list = new ObjectArray();
85 }
86 list.add(v);
87 break;
88 }
89 case Aggregate.STDDEV_POP:
90 case Aggregate.STDDEV_SAMP:
91 case Aggregate.VAR_POP:
92 case Aggregate.VAR_SAMP: {
93 double x = v.getDouble();
94 if(count == 1) {
95 sum = x;
96 vpn = 0;
97 } else {
98 double xs = sum - (x*(count-1));
99 vpn += (xs*xs) / count / (count-1);
100 sum += x;
101 }
102 break;
103 }
104 case Aggregate.EVERY:
105 v = v.convertTo(Value.BOOLEAN);
106 if(value == null) {
107 value = v;
108 } else {
109 value = ValueBoolean.get(value.getBoolean().booleanValue() && v.getBoolean().booleanValue());
110 }
111 break;
112 case Aggregate.SOME:
113 v = v.convertTo(Value.BOOLEAN);
114 if(value == null) {
115 value = v;
116 } else {
117 value = ValueBoolean.get(value.getBoolean().booleanValue() || v.getBoolean().booleanValue());
118 }
119 break;
120 default:
121 throw Message.getInternalError("type="+aggregateType);
122 }
123 }
124
125 ObjectArray getList() {
126 return list;
127 }
128
129 Value getValue(Database database, boolean distinct) throws SQLException {
130 if(distinct) {
131 count = 0;
132 groupDistinct(database);
133 }
134 Value v = null;
135 switch(aggregateType) {
136 case Aggregate.SELECTIVITY: {
137 int s = 0;
138 if(count == 0) {
139 s = 0;
140 } else {
141 sum += distinctValues.size();
142 sum = (100 * sum / count);
143 s = (int)sum;
144 s = s <= 0 ? 1 : s > 100 ? 100 : s;
145 }
146 v = ValueInt.get(s);
147 break;
148 }
149 case Aggregate.COUNT:
150 case Aggregate.COUNT_ALL:
151 v = ValueInt.get(count);
152 break;
153 case Aggregate.SUM:
154 case Aggregate.MIN:
155 case Aggregate.MAX:
156 case Aggregate.SOME:
157 case Aggregate.EVERY:
158 v = value;
159 break;
160 case Aggregate.AVG:
161 if(value != null) {
162 v = divide(value, count);
163 }
164 break;
165 case Aggregate.GROUP_CONCAT:
166 return null;
167 case Aggregate.STDDEV_POP: {
168 if(count < 1) {
169 return ValueNull.INSTANCE;
170 }
171 v = ValueDouble.get(Math.sqrt(vpn / count));
172 break;
173 }
174 case Aggregate.STDDEV_SAMP: {
175 if(count < 2) {
176 return ValueNull.INSTANCE;
177 }
178 v = ValueDouble.get(Math.sqrt(vpn / (count-1)));
179 break;
180 }
181 case Aggregate.VAR_POP: {
182 if(count < 1) {
183 return ValueNull.INSTANCE;
184 }
185 v = ValueDouble.get(vpn / count);
186 break;
187 }
188 case Aggregate.VAR_SAMP: {
189 if(count < 2) {
190 return ValueNull.INSTANCE;
191 }
192 v = ValueDouble.get(vpn / (count-1));
193 break;
194 }
195 default:
196 throw Message.getInternalError("type="+aggregateType);
197 }
198 return v == null ? ValueNull.INSTANCE : v;
199 }
200
201 private Value divide(Value a, int count) throws SQLException {
202 if(count == 0) {
203 return ValueNull.INSTANCE;
204 }
205 int type = Value.getHigherOrder(a.getType(), Value.INT);
206 Value b = ValueInt.get(count).convertTo(type);
207 a = a.convertTo(type).divide(b);
208 return a;
209 }
210
211 private void groupDistinct(Database database) throws SQLException {
212 if(distinctValues == null) {
213 return;
214 }
215 if(aggregateType == Aggregate.COUNT) {
216 count = distinctValues.size();
217 } else {
218 count = 0;
219 ObjectArray l2 = distinctValues.keys();
220 for(int i=0; i<l2.size(); i++) {
221 add(database, false, (Value)l2.get(i));
222 }
223 }
224 }
225
226 }
227 |
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