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1
2
3 package com.db4odoc.querymode;
4
5 import java.io.File  ;
6 import com.db4o.Db4o;
7 import com.db4o.ObjectContainer;
8 import com.db4o.ObjectSet;
9 import com.db4o.config.QueryEvaluationMode;
10 import com.db4o.query.Query;
11 import com.db4o.tools.QueryStats;
12
13
14
15 public class QueryModesExample {
16 public final static String YAPFILENAME="formula1.yap";
17
18 public static void main(String [] args) {
19 Db4o.configure().objectClass(Pilot.class).objectField("points").indexed(true);
20 testImmediateChanged();
26 }
27
29 public static void fillUpDB(int pilotCount){
30 new File (YAPFILENAME).delete();
31 ObjectContainer db=Db4o.openFile(YAPFILENAME);
32 try {
33 for (int i=0; i<pilotCount;i++){
34 addPilot(db,i);
35 }
36 }
37 finally {
38 db.close();
39 }
40 }
41
43 private static void addPilot(ObjectContainer db, int points) {
44 Pilot pilot = new Pilot("Tester", points);
45 db.set(pilot);
46 }
47
49 public static void testImmediateQueries() {
50 System.out.println("Testing query performance on 10000 pilot objects in Immediate mode");
51 fillUpDB(10000);
52 ObjectContainer db = Db4o.openFile(YAPFILENAME);
53 try {
54 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.IMMEDIATE);
55 QueryStats stats = new QueryStats();
56 stats.connect(db);
57 Query query = db.query();
58 query.constrain(Pilot.class);
59 query.descend("points").constrain(99).greater();
60 query.execute();
61 long executionTime = stats.executionTime();
62 System.out.println("Query execution time: " + executionTime);
63 } finally {
64 db.close();
65 }
66 }
67
69 public static void testLazyQueries() {
70 System.out.println("Testing query performance on 10000 pilot objects in Lazy mode");
71 fillUpDB(10000);
72 ObjectContainer db = Db4o.openFile(YAPFILENAME);
73 try {
74 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.LAZY);
75 QueryStats stats = new QueryStats();
76 stats.connect(db);
77 Query query = db.query();
78 query.constrain(Pilot.class);
79 query.descend("points").constrain(99).greater();
80 query.execute();
81 long executionTime = stats.executionTime();
82 System.out.println("Query execution time: " + executionTime);
83 } finally {
84 db.close();
85 }
86 }
87
89 public static void testLazyConcurrent() {
90 System.out.println("Testing lazy mode with concurrent modifications");
91 fillUpDB(10);
92 ObjectContainer db = Db4o.openFile(YAPFILENAME);
93 try {
94 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.LAZY);
95 Query query1 = db.query();
96 query1.constrain(Pilot.class);
97 query1.descend("points").constrain(5).smaller();
98 ObjectSet result1 = query1.execute();
99
100 Query query2 = db.query();
101 query2.constrain(Pilot.class);
102 query2.descend("points").constrain(1);
103 ObjectSet result2 = query2.execute();
104 Pilot pilotToDelete = (Pilot)result2.get(0);
105 System.out.println("Pilot to be deleted: " + pilotToDelete);
106 db.delete(pilotToDelete);
107 Pilot pilot = new Pilot("Tester",2);
108 System.out.println("Pilot to be added: " + pilot);
109 db.set(pilot);
110
111 System.out.println("Query result after changing from the same transaction");
112 listResult(result1);
113 } finally {
114 db.close();
115 }
116 }
117
119 public static void listResult(ObjectSet result) {
120 while(result.hasNext()) {
121 System.out.println(result.next());
122 }
123 }
124
126 public static void testSnapshotQueries() {
127 System.out.println("Testing query performance on 10000 pilot objects in Snapshot mode");
128 fillUpDB(10000);
129 ObjectContainer db = Db4o.openFile(YAPFILENAME);
130 try {
131 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.SNAPSHOT);
132 QueryStats stats = new QueryStats();
133 stats.connect(db);
134 Query query = db.query();
135 query.constrain(Pilot.class);
136 query.descend("points").constrain(99).greater();
137 query.execute();
138 long executionTime = stats.executionTime();
139 System.out.println("Query execution time: " + executionTime);
140 } finally {
141 db.close();
142 }
143 }
144
146 public static void testSnapshotConcurrent() {
147 System.out.println("Testing snapshot mode with concurrent modifications");
148 fillUpDB(10);
149 ObjectContainer db = Db4o.openFile(YAPFILENAME);
150 try {
151 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.SNAPSHOT);
152 Query query1 = db.query();
153 query1.constrain(Pilot.class);
154 query1.descend("points").constrain(5).smaller();
155 ObjectSet result1 = query1.execute();
156
157 Query query2 = db.query();
158 query2.constrain(Pilot.class);
159 query2.descend("points").constrain(1);
160 ObjectSet result2 = query2.execute();
161 Pilot pilotToDelete = (Pilot)result2.get(0);
162 System.out.println("Pilot to be deleted: " + pilotToDelete);
163 db.delete(pilotToDelete);
164 Pilot pilot = new Pilot("Tester",2);
165 System.out.println("Pilot to be added: " + pilot);
166 db.set(pilot);
167
168 System.out.println("Query result after changing from the same transaction");
169 listResult(result1);
170 } finally {
171 db.close();
172 }
173 }
174
176
177 public static void testImmediateChanged() {
178 System.out.println("Testing immediate mode with field changes");
179 fillUpDB(10);
180 ObjectContainer db = Db4o.openFile(YAPFILENAME);
181 try {
182 db.ext().configure().queries().evaluationMode(QueryEvaluationMode.IMMEDIATE);
183 Query query1 = db.query();
184 query1.constrain(Pilot.class);
185 query1.descend("points").constrain(5).smaller();
186 ObjectSet result1 = query1.execute();
187
188 Query query2 = db.query();
190 query2.constrain(Pilot.class);
191 query2.descend("points").constrain(2);
192 ObjectSet result2 = query2.execute();
193 Pilot pilot2 = (Pilot)result2.get(0);
194 pilot2.addPoints(22);
195 db.set(pilot2);
196 listResult(result1);
197 } finally {
198 db.close();
199 }
200 }
201 }
203 |
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