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1
5 package org.h2.index;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Constants;
10 import org.h2.engine.DbObject;
11 import org.h2.engine.Session;
12 import org.h2.message.Message;
13 import org.h2.message.Trace;
14 import org.h2.result.Row;
15 import org.h2.result.SearchRow;
16 import org.h2.schema.SchemaObject;
17 import org.h2.table.Column;
18 import org.h2.table.Table;
19 import org.h2.util.StringUtils;
20 import org.h2.value.Value;
21 import org.h2.value.ValueNull;
22
23
26 public abstract class Index extends SchemaObject {
27
28 protected Column[] columns;
29 protected int[] columnIndex;
30 protected Table table;
31 public IndexType indexType;
32 public static final int EMPTY_HEAD = -1;
33 protected int rowCount;
34
35 public Index(Table table, int id, String name, Column[] columns, IndexType indexType) {
36 super(table.getSchema(), id, name, Trace.INDEX);
37 this.indexType = indexType;
38 this.table = table;
39 if(columns != null) {
40 this.columns = columns;
41 columnIndex = new int[columns.length];
42 for(int i=0; i<columns.length; i++) {
43 columnIndex[i] = columns[i].getColumnId();
44 }
45 }
46 }
47
48 public SQLException getDuplicateKeyException() {
49 StringBuffer buff = new StringBuffer ();
50 buff.append(getName());
51 buff.append(" ");
52 buff.append(" ON ");
53 buff.append(table.getSQL());
54 buff.append("(");
55 buff.append(getColumnListSQL());
56 buff.append(")");
57 return Message.getSQLException(Message.DUPLICATE_KEY_1, buff.toString());
58 }
59
60 public String getPlanSQL() {
61 return getSQL();
62 }
63
64 public void removeChildrenAndResources(Session session) throws SQLException {
65 table.removeIndex(this);
66 remove(session);
67 }
68
69 public abstract void close(Session session) throws SQLException ;
70 public abstract void add(Session session, Row row) throws SQLException ;
71 public abstract void remove(Session session, Row row) throws SQLException ;
72 public abstract Cursor find(Session session, SearchRow first, SearchRow last) throws SQLException ;
73 public abstract int getCost(int[] masks) throws SQLException ;
74 public abstract void remove(Session session) throws SQLException ;
75 public abstract void truncate(Session session) throws SQLException ;
76 public abstract boolean canGetFirstOrLast(boolean first);
77 public abstract Value findFirstOrLast(Session session, boolean first) throws SQLException ;
78 public abstract boolean needRebuild();
79
80 public int getRowCount() {
81 return rowCount;
82 }
83
84 public int getLookupCost(int rowCount) {
85 return 2;
86 }
87
88 public int getCostRangeIndex(int[] masks, int rowCount) throws SQLException {
89 rowCount += Constants.COST_ROW_OFFSET;
90 int cost = rowCount;
91 int totalSelectivity = 0;
92 for (int i = 0; masks != null && i < columns.length; i++) {
93 Column column = columns[i];
94 int index = column.getColumnId();
95 int mask = masks[index];
96 if ((mask & IndexCondition.EQUALITY) == IndexCondition.EQUALITY) {
97 if(i == columns.length-1 && getIndexType().isUnique()) {
98 cost = getLookupCost(rowCount) + 1;
99 break;
100 }
101 totalSelectivity = 100 - ((100-totalSelectivity) * (100-column.getSelectivity()) / 100);
102 int distinctRows = rowCount * totalSelectivity / 100;
103 if(distinctRows <= 0) {
104 distinctRows = 1;
105 }
106 int rowsSelected = rowCount / distinctRows;
107 if(rowsSelected < 1) {
108 rowsSelected = 1;
109 }
110 cost = getLookupCost(rowCount) + rowsSelected;
111 } else if ((mask & IndexCondition.RANGE) == IndexCondition.RANGE) {
112 cost = getLookupCost(rowCount) + rowCount / 4;
113 break;
114 } else if ((mask & IndexCondition.START) == IndexCondition.START) {
115 cost = getLookupCost(rowCount) + rowCount / 3;
116 break;
117 } else if ((mask & IndexCondition.END) == IndexCondition.END) {
118 cost = rowCount / 3;
119 break;
120 } else {
121 break;
122 }
123 }
124 return cost;
125 }
126
127 public int compareRows(SearchRow rowData, SearchRow compare) throws SQLException {
128 for (int i = 0; i < columns.length; i++) {
129 int index = columnIndex[i];
130 Value v = compare.getValue(index);
131 if(v==null) {
132 return 0;
134 }
135 int c = compareValues(rowData.getValue(index), v);
136 if (c != 0) {
137 return c;
138 }
139 }
140 return 0;
141 }
142
143 public boolean isNull(Row newRow) {
144 for (int i = 0; i < columns.length; i++) {
145 int index = columnIndex[i];
146 Value v = newRow.getValue(index);
147 if(v == ValueNull.INSTANCE) {
148 return true;
149 }
150 }
151 return false;
152 }
153
154 public int compareKeys(SearchRow rowData, SearchRow compare) {
155 int k1 = rowData.getPos();
156 int k2 = compare.getPos();
157 if (k1 == k2) {
158 return 0;
159 }
160 return k1 > k2 ? 1 : -1;
161 }
162
163 private int compareValues(Value v1, Value v2) throws SQLException {
164 if (v1 == null) {
165 if (v2 == null) {
166 return 0;
167 }
168 return 1;
169 }
170 if (v2 == null) {
171 return -1;
172 }
173 return database.compareTypeSave(v1, v2);
174 }
175
176 public int getColumnIndex(Column col) {
177 for (int i = 0; i < columns.length; i++) {
178 if (columns[i] == col) {
179 return i;
180 }
181 }
182 return -1;
183 }
184
185 public String getColumnListSQL() {
186 StringBuffer buff = new StringBuffer ();
187 for (int i = 0; i < columns.length; i++) {
188 if (i > 0) {
189 buff.append(", ");
190 }
191 buff.append(columns[i].getSQL());
192 }
193 return buff.toString();
194 }
195
196 public String getCreateSQLForCopy(Table table, String quotedName) {
197 StringBuffer buff = new StringBuffer ();
198 buff.append("CREATE ");
199 buff.append(indexType.getSQL());
200 if(!indexType.isPrimaryKey()) {
201 buff.append(' ');
202 buff.append(quotedName);
203 }
204 buff.append(" ON ");
205 buff.append(table.getSQL());
206 if(comment != null) {
207 buff.append(" COMMENT ");
208 buff.append(StringUtils.quoteStringSQL(comment));
209 }
210 buff.append("(");
211 buff.append(getColumnListSQL());
212 buff.append(")");
213 return buff.toString();
214 }
215
216 public String getCreateSQL() {
217 return getCreateSQLForCopy(table, getSQL());
218 }
219
220 public Column[] getColumns() {
221 return columns;
222 }
223
224 public IndexType getIndexType() {
225 return indexType;
226 }
227
228 public int getType() {
229 return DbObject.INDEX;
230 }
231
232 public Table getTable() {
233 return table;
234 }
235
236 }
237 |
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