Attributes


1   /*
2   
3   This software is OSI Certified Open Source Software.
4   OSI Certified is a certification mark of the Open Source Initiative.
5   
6   The license (Mozilla version 1.0) can be read at the MMBase site.
7   See http://www.MMBase.org/license
8   
9   */
10  package org.mmbase.storage.implementation.database;
11  
12  /**
13   * This class defines the attributes names used by the default database storage manager classes.
14   * Specific storage managers may ignore or add their own attributes.
15   *
16   * @author Pierre van Rooden
17   * @since MMBase-1.7
18   * @version $Id: Attributes.java,v 1.14 2005/02/03 09:21:38 michiel Exp $
19   */
20  public final class Attributes {
21  
22      /**
23       * Attribute: <code>database-data-source</code>.
24       * The data source object used by the storage layer.
25       * This attribute is set by the storagelayer and returns a javax.sql.DataSource object.
26       * You should not set or configure this attribute (but you can retrieve it).
27       */
28      public static final String   DATA_SOURCE = "database-data-source";
29  
30      /**
31       * Option: <code>database-supports-transactions</code>.
32       * When true, the database supports transactions.
33       * The default is determined form the database, but you can override it.
34       */
35      public static final String   SUPPORTS_TRANSACTIONS = "database-supports-transactions";
36  
37      /**
38       * Option: <code>database-stores-binary-as-file</code>.
39       * When true, binary data is stored on disk, rather than in the database.
40       * If you set this option ou should also set the attribute {@link #BINARY_FILE_PATH}
41       * The default is <code>false</code>
42       */
43      public static final String   STORES_BINARY_AS_FILE = "database-stores-binary-as-file";
44  
45      /**
46       * Attribute: <code>database-binary-file-path</code>.
47       * The path to the directyory where binary files are to be stored if {@link #STORES_BINARY_AS_FILE} is true.
48       * The default is the WEB-INF/data directory of the mmbase web application.
49       * Note that if you specify a relative url, it is taken from the web application's webroot.
50       */
51      public static final String   BINARY_FILE_PATH = "database-binary-file-path";
52  
53      /**
54       * Option: <code>database-force-encode-text</code>.
55       * If true, the database layer will explicitly decode/encode strings using the MMBase encoding when
56       * storing and retrieving text from the database.
57       * The default is <code>false</code>
58       */
59      public static final String   FORCE_ENCODE_TEXT = "database-force-encode-text";
60  
61      /**
62       * If the database is ISO-8859-1, then you can switch this option to true, to store CP1252 in it.
63       */
64      public static final String   LIE_CP1252        = "database-lie-cp1252";
65  
66  
67      /**
68       * Option: <code>database-supports-blob</code>.
69       * When true, the driver/database used supports the JDBC getBlob() method.
70       * The default is <code>false</code>
71       */
72      public static final String   SUPPORTS_BLOB = "database-supports-blob";
73  
74      /**
75       * Option: <code>database-supports-composite-index</code>.
76       * When true, the database uses composite indices for 'key' fields.
77       * When false, it uses single indices (a separate index for each field)
78       * The default is <code>true</code>
79       */
80      public static final String   SUPPORTS_COMPOSITE_INDEX = "database-supports-composite-index";
81  
82      /**
83       * Attribute: <code>database-transaction-isolation-level</code>.
84       * The transaction isolation level used for connections to the database.
85       * This determines the level of transaction support.
86       * The default is determined from the database metadata.
87       */
88      public static final String   TRANSACTION_ISOLATION_LEVEL = "database-transaction-isolation-level";
89  
90      /**
91       * Option: <code>database-supports-data-definition</code>.
92       * If true, the data definiton (table structure) can be changed using ALTER TABLE statements.
93       * Some databses (such as Informix) may have trouble with ALTER TABLE statements on OO-tables.
94       * Turn this option false for tehse databses.
95       * The default is <code>true</code>
96       */
97      public static final String   SUPPORTS_DATA_DEFINITION = "database-supports-data-definition";
98  
99      /**
100      * Option: <code>database-remove-empty-definitions</code>.
101      * If this option is true, empty parenthesis in a table definition are removed.
102      * When you create a new table that extends form another table, but which doesn't add fields,
103      * you may get a statement that looks like: <br />
104      * <code>CREATE TABLE table1 () UNDER table2</code><br />
105      * This statement will fail udner a database such as Informix, which does not accept empty
106      * parenthesis, but instead expects: <br />
107      * <code>CREATE TABLE table1 UNDER table2</code><br />
108      * On the other hand, a database such as Postgresql DOES expect the parenthesis (and fails if
109      * they are ommitted.)
110      * The default is <code>false</code>
111      */
112     public static final String   REMOVE_EMPTY_DEFINITIONS = "database-remove-empty-definitions";
113 
114     /**
115      * Option: <code>sequence-buffer-size</code>.
116      * The sequence buffer size is the number of keys that MMBase caches in the storage layer.
117      * You can use this to minimize the nr of times MMBase accesses the database to generate a new
118      * object number.
119      * When not set, the value is assumed to be 1.
120      */
121     public static final String   SEQUENCE_BUFFER_SIZE = "sequence-buffer-size";
122 
123     /**
124      * Option: <code>trim-strings</code>.
125      * Some text fields for some databases need to be trimmed.
126      * The default is <code>false</code>
127      */
128     public static final String   TRIM_STRINGS = "trim-strings";
129 
130 }
131
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