Hibernate example source code file (performance.po)

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The Hibernate performance.po source code

# translation of performance.po to
# Xi Huang <xhuang@redhat.com>, 2006.
# Xi HUANG <xhuang@redhat.com>, 2007, 2009.
# translation of Collection_Mapping.po to
msgid ""
msgstr ""
"Project-Id-Version: performance\n"
"Report-Msgid-Bugs-To: http://bugs.kde.org\n"
"POT-Creation-Date: 2010-07-20 21:02+0000\n"
"PO-Revision-Date: 2010-03-15 15:27+1000\n"
"Last-Translator: Xi HUANG <xhuang@redhat.com>\n"
"Language-Team:  <en@li.org>\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Generator: KBabel 1.11.4\n"

#. Tag: title
#: performance.xml:31
#, no-c-format
msgid "Improving performance"
msgstr "提升性能"

#. Tag: title
#: performance.xml:34
#, no-c-format
msgid "Fetching strategies"
msgstr "抓取策略（Fetching strategies）"

#. Tag: para
#: performance.xml:36
#, no-c-format
msgid ""
"Hibernate uses a <emphasis>fetching strategy to retrieve "
"associated objects if the application needs to navigate the association. "
"Fetch strategies can be declared in the O/R mapping metadata, or over-ridden "
"by a particular HQL or <literal>Criteria query."
msgstr ""
"当应用程序需要在（Hibernate实体对象图的）关联关系间进行导航的时候，Hibernate "
"使用 <emphasis>抓取策略（fetching strategy） 获取关联对象。抓取策"
"略可以在 O/R 映射的元数据中声明，也可以在特定的 HQL 或<literal>条件查询"
"（Criteria Query）</literal>中重载声明。"

#. Tag: para
#: performance.xml:42
#, no-c-format
msgid "Hibernate3 defines the following fetching strategies:"
msgstr "Hibernate3 定义了如下几种抓取策略："

#. Tag: para
#: performance.xml:46
#, no-c-format
msgid ""
"<emphasis>Join fetching: Hibernate retrieves the associated "
"instance or collection in the same <literal>SELECT, using an "
"<literal>OUTER JOIN."
msgstr ""
"<emphasis>连接抓取（Join fetching）：Hibernate 通过在 "
"<literal>SELECT  语句使用 OUTER JOIN（外连接）来"
"获得对象的关联实例或者关联集合。 "

#. Tag: para
#: performance.xml:53
#, no-c-format
msgid ""
"<emphasis>Select fetching: a second SELECT is "
"used to retrieve the associated entity or collection. Unless you explicitly "
"disable lazy fetching by specifying <literal>lazy=\"false\", this "
"second select will only be executed when you access the association."
msgstr ""
"<emphasis>查询抓取（Select fetching）：另外发送一条 "
"<literal>SELECT 语句抓取当前对象的关联实体或集合。除非你显式的指定 "
"<literal>lazy=\"false\" 禁止 延迟抓取（lazy fetching），否则只有当"
"你真正访问关联关系的时候，才会执行第二条 select 语句。"

#. Tag: para
#: performance.xml:61
#, no-c-format
msgid ""
"<emphasis>Subselect fetching: a second SELECT "
"is used to retrieve the associated collections for all entities retrieved in "
"a previous query or fetch. Unless you explicitly disable lazy fetching by "
"specifying <literal>lazy=\"false\", this second select will only "
"be executed when you access the association."
msgstr ""
"<emphasis>子查询抓取（Subselect fetching）：另外发送一条  "
"<literal>SELECT 语句抓取在前面查询到（或者抓取到）的所有实体对象的"
"关联集合。除非你显式的指定 <literal>lazy=\"false\" 禁止延迟抓取"
"（lazy fetching），否则只有当你真正访问关联关系的时候，才会执行第二条 select "
"语句。"

#. Tag: para
#: performance.xml:70
#, no-c-format
msgid ""
"<emphasis>Batch fetching: an optimization strategy for select "
"fetching. Hibernate retrieves a batch of entity instances or collections in "
"a single <literal>SELECT by specifying a list of primary or "
"foreign keys."
msgstr ""
"<emphasis>批量抓取（Batch fetching）：对查询抓取的优化方案，通过指"
"定一个主键或外键列表，Hibernate 使用单条 <literal>SELECT 语句获取一"
"批对象实例或集合。"

#. Tag: para
#: performance.xml:77
#, no-c-format
msgid "Hibernate also distinguishes between:"
msgstr "Hibernate 会区分下列各种情况："

#. Tag: para
#: performance.xml:81
#, no-c-format
msgid ""
"<emphasis>Immediate fetching: an association, collection or "
"attribute is fetched immediately when the owner is loaded."
msgstr ""
"<emphasis>Immediate fetching，立即抓取：当宿主被加载时，关联、集合"
"或属性被立即抓取。"

#. Tag: para
#: performance.xml:87
#, no-c-format
msgid ""
"<emphasis>Lazy collection fetching: a collection is fetched when "
"the application invokes an operation upon that collection. This is the "
"default for collections."
msgstr ""
"<emphasis>Lazy collection fetching，延迟集合抓取：直到应用程序对集"
"合进行了一次操作时，集合才被抓取（对集合而言这是默认行为）。"

#. Tag: para
#: performance.xml:93
#, no-c-format
msgid ""
"<emphasis>\"Extra-lazy\" collection fetching: individual elements "
"of the collection are accessed from the database as needed. Hibernate tries "
"not to fetch the whole collection into memory unless absolutely needed. It "
"is suitable for large collections."
msgstr ""
"<emphasis>\"Extra-lazy\" collection fetching,\"Extra-lazy\" 集合抓取: a single-valued association is fetched "
"when a method other than the identifier getter is invoked upon the "
"associated object."
msgstr ""
"<emphasis>Proxy fetching，代理抓取：对返回单值的关联而言，当其某个"
"方法被调用，而非对其关键字进行 get 操作时才抓取。"

#. Tag: para
#: performance.xml:107
#, no-c-format
msgid ""
"<emphasis>\"No-proxy\" fetching: a single-valued association is "
"fetched when the instance variable is accessed. Compared to proxy fetching, "
"this approach is less lazy; the association is fetched even when only the "
"identifier is accessed. It is also more transparent, since no proxy is "
"visible to the application. This approach requires buildtime bytecode "
"instrumentation and is rarely necessary."
msgstr ""
"<emphasis>\"No-proxy\" fetching，非代理抓取：对返回单值的关联而"
"言，当实例变量被访问的时候进行抓取。与上面的代理抓取相比，这种方法没有那么“延"
"迟”得厉害（就算只访问标识符，也会导致关联抓取）但是更加透明，因为对应用程序来"
"说，不再看到 proxy。这种方法需要在编译期间进行字节码增强操作，因此很少需要用"
"到。"

#. Tag: para
#: performance.xml:117
#, no-c-format
msgid ""
"<emphasis>Lazy attribute fetching: an attribute or single valued "
"association is fetched when the instance variable is accessed. This approach "
"requires buildtime bytecode instrumentation and is rarely necessary."
msgstr ""
"<emphasis>Lazy attribute fetching，属性延迟加载：对属性或返回单值"
"的关联而言，当其实例变量被访问的时候进行抓取。需要编译期字节码强化，因此这一"
"方法很少是必要的。"

#. Tag: para
#: performance.xml:124
#, no-c-format
msgid ""
"We have two orthogonal notions here: <emphasis>when is the "
"association fetched and <emphasis>how is it fetched. It is "
"important that you do not confuse them. We use <literal>fetch to "
"tune performance. We can use <literal>lazy to define a contract "
"for what data is always available in any detached instance of a particular "
"class."
msgstr ""
"这里有两个正交的概念：关联<emphasis>何时被抓取，以及被如"
"何</emphasis>抓取（会采用什么样的 SQL 语句）。注意不要混淆它们。我们使用"
"<literal>抓取来改善性能。我们使用延迟来定义一些"
"契约，对某特定类的某个脱管的实例，知道有哪些数据是可以使用的。"

#. Tag: title
#: performance.xml:132
#, no-c-format
msgid "Working with lazy associations"
msgstr "操作延迟加载的关联"

#. Tag: para
#: performance.xml:134
#, no-c-format
msgid ""
"By default, Hibernate3 uses lazy select fetching for collections and lazy "
"proxy fetching for single-valued associations. These defaults make sense for "
"most associations in the majority of applications."
msgstr ""
"默认情况下，Hibernate 3 对集合使用延迟 select 抓取，对返回单值的关联使用延迟"
"代理抓取。对几乎是所有的应用而言，其绝大多数的关联，这种策略都是有效的。"

#. Tag: para
#: performance.xml:138
#, no-c-format
msgid ""
"If you set <literal>hibernate.default_batch_fetch_size, Hibernate "
"will use the batch fetch optimization for lazy fetching. This optimization "
"can also be enabled at a more granular level."
msgstr ""
"假若你设置了 <literal>hibernate.default_batch_fetch_size，"
"Hibernate 会对延迟加载采取批量抓取优化措施（这种优化也可能会在更细化的级别打"
"开）。"

#. Tag: para
#: performance.xml:142
#, no-c-format
msgid ""
"Please be aware that access to a lazy association outside of the context of "
"an open Hibernate session will result in an exception. For example:"
msgstr ""
"然而，你必须了解延迟抓取带来的一个问题。在一个打开的 Hibernate session 上下文"
"之外调用延迟集合会导致一次意外。比如： "

#. Tag: programlisting
#: performance.xml:146
#, fuzzy, no-c-format
msgid ""
"s = sessions.openSession();\n"
"Transaction tx = s.beginTransaction();\n"
"            \n"
"User u = (User) s.createQuery(\"from User u where u.name=:userName\")\n"
"    .setString(\"userName\", userName).uniqueResult();\n"
"Map permissions = u.getPermissions();\n"
"\n"
"tx.commit();\n"
"s.close();\n"
"\n"
"Integer accessLevel = (Integer) permissions.get(\"accounts\");  // Error!"
msgstr ""
"<![CDATA[s = sessions.openSession();\n"
"Transaction tx = s.beginTransaction();\n"
"            \n"
"User u = (User) s.createQuery(\"from User u where u.name=:userName\")\n"
"    .setString(\"userName\", userName).uniqueResult();\n"
"Map permissions = u.getPermissions();\n"
"\n"
"tx.commit();\n"
"s.close();\n"
"\n"
"Integer accessLevel = (Integer) permissions.get(\"accounts\");  // Error!]]>"

#. Tag: para
#: performance.xml:148
#, no-c-format
msgid ""
"Since the permissions collection was not initialized when the "
"<literal>Session was closed, the collection will not be able to "
"load its state. <emphasis>Hibernate does not support lazy initialization for "
"detached objects</emphasis>. This can be fixed by moving the code that reads "
"from the collection to just before the transaction is committed."
msgstr ""
"在 <literal>Session 关闭后，permessions 集合将是未实例化的、不再可"
"用，因此无法正常载入其状态。 <emphasis>Hibernate 对脱管对象不支持延迟实例化 for the association mapping. "
"However, it is intended that lazy initialization be used for almost all "
"collections and associations. If you define too many non-lazy associations "
"in your object model, Hibernate will fetch the entire database into memory "
"in every transaction."
msgstr ""
"除此之外，通过对关联映射指定 <literal>lazy=\"false\"，我们也可以使"
"用非延迟的集合或关联。但是，对绝大部分集合来说，更推荐使用延迟方式抓取数据。"
"如果在你的对象模型中定义了太多的非延迟关联，Hibernate 最终几乎需要在每个事务"
"中载入整个数据库到内存中。"

#. Tag: para
#: performance.xml:162
#, no-c-format
msgid ""
"On the other hand, you can use join fetching, which is non-lazy by nature, "
"instead of select fetching in a particular transaction. We will now explain "
"how to customize the fetching strategy. In Hibernate3, the mechanisms for "
"choosing a fetch strategy are identical for single-valued associations and "
"collections."
msgstr ""
"但是，另一方面，在一些特殊的事务中，我们也经常需要使用到连接抓取（它本身上就"
"是非延迟的），以代替查询抓取。 下面我们将会很快明白如何具体的定制 Hibernate "
"中的抓取策略。在 Hibernate3 中，具体选择哪种抓取策略的机制是和选择 单值关联或"
"集合关联相一致的。 "

#. Tag: title
#: performance.xml:170
#, no-c-format
msgid "Tuning fetch strategies"
msgstr "调整抓取策略（Tuning fetch strategies）"

#. Tag: para
#: performance.xml:172
#, no-c-format
msgid ""
"Select fetching (the default) is extremely vulnerable to N+1 selects "
"problems, so we might want to enable join fetching in the mapping document:"
msgstr ""
"查询抓取（默认的）在 N+1 查询的情况下是极其脆弱的，因此我们可能会要求在映射文"
"档中定义使用连接抓取："

#. Tag: programlisting
#: performance.xml:176
#, fuzzy, no-c-format
msgid ""
"<set name=\"permissions\"\n"
"            fetch=\"join\">\n"
"    <key column=\"userId\"/>\n"
"    <one-to-many class=\"Permission\"/>\n"
"</set"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:180
#, no-c-format
msgid ""
"The <literal>fetch strategy defined in the mapping document "
"affects:"
msgstr ""
"在映射文档中定义的<literal>抓取策略将会对以下列表条目产生影响："

#. Tag: para
#: performance.xml:185
#, no-c-format
msgid "retrieval via <literal>get() or load()"
msgstr ""
"通过 <literal>get() 或 load() 方法取得数据。"

#. Tag: para
#: performance.xml:190
#, no-c-format
msgid "retrieval that happens implicitly when an association is navigated"
msgstr "只有在关联之间进行导航时，才会隐式的取得数据。"

#. Tag: para
#: performance.xml:195
#, no-c-format
msgid "<literal>Criteria queries"
msgstr "条件查询"

#. Tag: para
#: performance.xml:199
#, no-c-format
msgid "HQL queries if <literal>subselect fetching is used"
msgstr "使用了 <literal>subselect 抓取的 HQL 查询"

#. Tag: para
#: performance.xml:204
#, no-c-format
msgid ""
"Irrespective of the fetching strategy you use, the defined non-lazy graph is "
"guaranteed to be loaded into memory. This might, however, result in several "
"immediate selects being used to execute a particular HQL query."
msgstr ""
"不管你使用哪种抓取策略，定义为非延迟的类图会被保证一定装载入内存。注意这可能"
"意味着在一条 HQL 查询后紧跟着一系列的查询。 "

#. Tag: para
#: performance.xml:209
#, no-c-format
msgid ""
"Usually, the mapping document is not used to customize fetching. Instead, we "
"keep the default behavior, and override it for a particular transaction, "
"using <literal>left join fetch in HQL. This tells Hibernate to "
"fetch the association eagerly in the first select, using an outer join. In "
"the <literal>Criteria query API, you would use "
"<literal>setFetchMode(FetchMode.JOIN)."
msgstr ""
"通常情况下，我们并不使用映射文档进行抓取策略的定制。更多的是，保持其默认值，"
"然后在特定的事务中， 使用 HQL 的<literal>左连接抓取（left join fetch） API 中，应该调用 "
"<literal>setFetchMode（FetchMode.JOIN）语句。 "

#. Tag: para
#: performance.xml:216
#, no-c-format
msgid ""
"If you want to change the fetching strategy used by <literal>get() "
"or <literal>load(), you can use a Criteria "
"query. For example:"
msgstr ""
"也许你喜欢仅仅通过条件查询，就可以改变 <literal>get() 或 "
"<literal>load() 语句中的数据抓取策略。例如： "

#. Tag: programlisting
#: performance.xml:220
#, fuzzy, no-c-format
msgid ""
"User user = (User) session.createCriteria(User.class)\n"
"                .setFetchMode(\"permissions\", FetchMode.JOIN)\n"
"                .add( Restrictions.idEq(userId) )\n"
"                .uniqueResult();"
msgstr ""
"<![CDATA[User user = (User) session.createCriteria(User.class)\n"
"                .setFetchMode(\"permissions\", FetchMode.JOIN)\n"
"                .add( Restrictions.idEq(userId) )\n"
"                .uniqueResult();]]>"

#. Tag: para
#: performance.xml:222
#, no-c-format
msgid ""
"This is Hibernate's equivalent of what some ORM solutions call a \"fetch plan"
"\"."
msgstr ""
"这就是其他 ORM 解决方案的“抓取计划（fetch plan）”在 Hibernate 中的等价物。"

#. Tag: para
#: performance.xml:225
#, no-c-format
msgid ""
"A completely different approach to problems with N+1 selects is to use the "
"second-level cache."
msgstr "截然不同的一种避免 N+1 次查询的方法是，使用二级缓存。 "

#. Tag: title
#: performance.xml:230
#, no-c-format
msgid "Single-ended association proxies"
msgstr "单端关联代理（Single-ended association proxies）"

#. Tag: para
#: performance.xml:232
#, no-c-format
msgid ""
"Lazy fetching for collections is implemented using Hibernate's own "
"implementation of persistent collections. However, a different mechanism is "
"needed for lazy behavior in single-ended associations. The target entity of "
"the association must be proxied. Hibernate implements lazy initializing "
"proxies for persistent objects using runtime bytecode enhancement which is "
"accessed via the CGLIB library."
msgstr ""
"在 Hinerbate 中，对集合的延迟抓取的采用了自己的实现方法。但是，对于单端关联的"
"延迟抓取，则需要采用 其他不同的机制。单端关联的目标实体必须使用代理，"
"Hihernate 在运行期二进制级（通过优异的 CGLIB 库）， 为持久对象实现了延迟载入"
"代理。 "

#. Tag: para
#: performance.xml:239
#, no-c-format
msgid ""
"At startup, Hibernate3 generates proxies by default for all persistent "
"classes and uses them to enable lazy fetching of <literal>many-to-oneone-to-one associations."
msgstr ""
"默认的，Hibernate3 将会为所有的持久对象产生代理（在启动阶段），然后使用他们实"
"现 <literal>多对一（many-to-one）关联和一对一（one-to-"
"one）</literal> 关联的延迟抓取。 "

#. Tag: para
#: performance.xml:244
#, no-c-format
msgid ""
"The mapping file may declare an interface to use as the proxy interface for "
"that class, with the <literal>proxy attribute. By default, "
"Hibernate uses a subclass of the class. <emphasis>The proxied class must "
"implement a default constructor with at least package visibility. This "
"constructor is recommended for all persistent classes</emphasis>."
msgstr ""
"在映射文件中，可以通过设置 <literal>proxy 属性为目标 class 声明一个"
"接口供代理接口使用。 默认的，Hibernate 将会使用该类的一个子类。<emphasis>注"
"意：被代理的类必须实现一个至少包可见的默认构造函数，我们建议所有的持久类都应"
"拥有这样的构造函数。</emphasis>"

#. Tag: para
#: performance.xml:251
#, no-c-format
msgid ""
"There are potential problems to note when extending this approach to "
"polymorphic classes.For example:"
msgstr "在如此方式定义一个多态类的时候，有许多值得注意的常见性的问题，例如： "

#. Tag: programlisting
#: performance.xml:254
#, fuzzy, no-c-format
msgid ""
"<class name=\"Cat\" proxy=\"Cat\">\n"
"    ......\n"
"    <subclass name=\"DomesticCat\">\n"
"        .....\n"
"    </subclass>\n"
"</class>"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:256
#, no-c-format
msgid ""
"Firstly, instances of <literal>Cat will never be castable to "
"<literal>DomesticCat, even if the underlying instance is an "
"instance of <literal>DomesticCat:"
msgstr ""
"首先，<literal>Cat 实例永远不可以被强制转换为 "
"<literal>DomesticCat，即使它本身就是 DomesticCat:"
msgstr "其次，代理的“<literal>==”可能不再成立。 "

#. Tag: programlisting
#: performance.xml:265
#, fuzzy, no-c-format
msgid ""
"Cat cat = (Cat) session.load(Cat.class, id);            // instantiate a Cat "
"proxy\n"
"DomesticCat dc = \n"
"        (DomesticCat) session.load(DomesticCat.class, id);  // acquire new "
"DomesticCat proxy!\n"
"System.out.println(cat==dc);                            // false"
msgstr ""
"<![CDATA[Cat cat = (Cat) session.load(Cat.class, id);            // "
"instantiate a Cat proxy\n"
"DomesticCat dc = \n"
"        (DomesticCat) session.load(DomesticCat.class, id);  // acquire new "
"DomesticCat proxy!\n"
"System.out.println(cat==dc);                            // false]]>"

#. Tag: para
#: performance.xml:267
#, no-c-format
msgid ""
"However, the situation is not quite as bad as it looks. Even though we now "
"have two references to different proxy objects, the underlying instance will "
"still be the same object:"
msgstr ""
"虽然如此，但实际情况并没有看上去那么糟糕。虽然我们现在有两个不同的引用，分别"
"指向这两个不同的代理对象，但实际上，其底层应该是同一个实例对象："

#. Tag: programlisting
#: performance.xml:271
#, fuzzy, no-c-format
msgid ""
"cat.setWeight(11.0);  // hit the db to initialize the proxy\n"
"System.out.println( dc.getWeight() );  // 11.0"
msgstr ""
"<![CDATA[cat.setWeight(11.0);  // hit the db to initialize the proxy\n"
"System.out.println( dc.getWeight() );  // 11.0]]>"

#. Tag: para
#: performance.xml:273
#, no-c-format
msgid ""
"Third, you cannot use a CGLIB proxy for a <literal>final class or "
"a class with any <literal>final methods."
msgstr ""
"第三，你不能对 <literal>final 类或具有 final 方"
"法的类使用 CGLIB 代理。"

#. Tag: para
#: performance.xml:276
#, no-c-format
msgid ""
"Finally, if your persistent object acquires any resources upon instantiation "
"(e.g. in initializers or default constructor), then those resources will "
"also be acquired by the proxy. The proxy class is an actual subclass of the "
"persistent class."
msgstr ""
"最后，如果你的持久化对象在实例化时需要某些资源（例如，在实例化方法、默认构造"
"方法中），那么代理对象也同样需要使用这些资源。实际上，代理类是持久化类的子"
"类。"

#. Tag: para
#: performance.xml:281
#, no-c-format
msgid ""
"These problems are all due to fundamental limitations in Java's single "
"inheritance model. To avoid these problems your persistent classes must each "
"implement an interface that declares its business methods. You should "
"specify these interfaces in the mapping file where <literal>CatImplCat and "
"<literal>DomesticCatImpl implements the interface "
"<literal>DomesticCat. For example:"
msgstr ""
"这些问题都源于 Java 的单根继承模型的天生限制。如果你希望避免这些问题，那么你"
"的每个持久化类必须实现一个接口， 在此接口中已经声明了其业务方法。然后，你需要"
"在映射文档中再指定这些接口，如 <literal>CatImpl 实现 CatDomesticCatImpl 实现 DomesticCat"

#. Tag: para
#: performance.xml:291
#, no-c-format
msgid ""
"Then proxies for instances of <literal>Cat and "
"<literal>DomesticCat can be returned by load() "
"or <literal>iterate()."
msgstr ""
"然后，<literal>load() 和 iterate() 永远也不会返"
"回 <literal>Cat 和 DomesticCat 实例的代理。"

#. Tag: programlisting
#: performance.xml:295
#, fuzzy, no-c-format
msgid ""
"Cat cat = (Cat) session.load(CatImpl.class, catid);\n"
"Iterator iter = session.createQuery(\"from CatImpl as cat where cat."
"name='fritz'\").iterate();\n"
"Cat fritz = (Cat) iter.next();"
msgstr ""
"<![CDATA[Cat cat = (Cat) session.load(CatImpl.class, catid);\n"
"Iterator iter = session.createQuery(\"from CatImpl as cat where cat."
"name='fritz'\").iterate();\n"
"Cat fritz = (Cat) iter.next();]]>"

#. Tag: title
#: performance.xml:298
#, no-c-format
msgid "Note"
msgstr "注意"

#. Tag: para
#: performance.xml:300
#, no-c-format
msgid "<literal>list() does not usually return proxies."
msgstr "<literal>list() 通常不返回代理。"

#. Tag: para
#: performance.xml:304
#, no-c-format
msgid ""
"Relationships are also lazily initialized. This means you must declare any "
"properties to be of type <literal>Cat, not CatImpl，而不是 CatImpl。"

#. Tag: para
#: performance.xml:308
#, no-c-format
msgid ""
"Certain operations do <emphasis>not require proxy initialization:"
msgstr "有些方法中是<emphasis>不需要代理初始化的："

#. Tag: para
#: performance.xml:313
#, no-c-format
msgid ""
"<literal>equals(): if the persistent class does not override "
"<literal>equals()"
msgstr ""
"<literal>equals() 方法，如果持久类没有重载 equals(): if the persistent class does not override "
"<literal>hashCode()"
msgstr ""
"<literal>hashCode()：如果持久类没有重载 hashCode()hashCode()."
msgstr ""
"Hibernate 将会识别出那些重载了 <literal>equals()、或 "
"<literal>hashCode() 方法的持久化类。"

#. Tag: para
#: performance.xml:330
#, no-c-format
msgid ""
"By choosing <literal>lazy=\"no-proxy\" instead of the default "
"<literal>lazy=\"proxy\", you can avoid problems associated with "
"typecasting. However, buildtime bytecode instrumentation is required, and "
"all operations will result in immediate proxy initialization."
msgstr ""
"若选择 <literal>lazy=\"no-proxy\" 而非默认的 lazy=\"proxy"
"\"</literal>，我们可以避免类型转换带来的问题。然而，这样我们就需要编译期字节"
"码增强，并且所有的操作都会导致立刻进行代理初始化。 "

#. Tag: title
#: performance.xml:338
#, no-c-format
msgid "Initializing collections and proxies"
msgstr "实例化集合和代理（Initializing collections and proxies）"

#. Tag: para
#: performance.xml:340
#, no-c-format
msgid ""
"A <literal>LazyInitializationException will be thrown by Hibernate "
"if an uninitialized collection or proxy is accessed outside of the scope of "
"the <literal>Session, i.e., when the entity owning the collection "
"or having the reference to the proxy is in the detached state."
msgstr ""
"在 <literal>Session 范围之外访问未初始化的集合或代理，Hibernate 将"
"会抛出 <literal>LazyInitializationException 异常。也就是说，在分离"
"状态下，访问一个实体所拥有的集合，或者访问其指向代理的属性时，会引发此异常。 "

#. Tag: para
#: performance.xml:346
#, no-c-format
msgid ""
"Sometimes a proxy or collection needs to be initialized before closing the "
"<literal>Session. You can force initialization by calling "
"<literal>cat.getSex() or cat.getKittens().size() 或者 cat."
"getKittens().size()</literal> 之类的方法来确保这一点。 但是这样的程序会造成读"
"者的疑惑，也不符合通常的代码规范。 "

#. Tag: para
#: performance.xml:353
#, no-c-format
msgid ""
"The static methods <literal>Hibernate.initialize() and "
"<literal>Hibernate.isInitialized(), provide the application with a "
"convenient way of working with lazily initialized collections or proxies. "
"<literal>Hibernate.initialize(cat) will force the initialization "
"of a proxy, <literal>cat, as long as its SessionHibernate.initialize( cat.getKittens() ) 为你的应用程序提供了一个"
"便捷的途径来延迟加载集合或代理。 只要它的 Session 处于 open 状态，"
"<literal>Hibernate.initialize(cat) 将会为 cat 强制对代理实例化。同"
"样，<literal>Hibernate.initialize(cat.getKittens()) 对 kittens 的集"
"合具有同样的功能。 "

#. Tag: para
#: performance.xml:362
#, no-c-format
msgid ""
"Another option is to keep the <literal>Session open until all "
"required collections and proxies have been loaded. In some application "
"architectures, particularly where the code that accesses data using "
"Hibernate, and the code that uses it are in different application layers or "
"different physical processes, it can be a problem to ensure that the "
"<literal>Session is open when a collection is initialized. There "
"are two basic ways to deal with this issue:"
msgstr ""
"还有另外一种选择，就是保持 <literal>Session 一直处于 open 状态，直"
"到所有需要的集合或代理都被载入。 在某些应用架构中，特别是对于那些使用 "
"Hibernate 进行数据访问的代码，以及那些在不同应用层和不同物理进程中使用 "
"Hibernate 的代码。 在集合实例化时，如何保证 <literal>Session 处于 "
"open 状态经常会是一个问题。有两种方法可以解决此问题： "

#. Tag: para
#: performance.xml:372
#, no-c-format
msgid ""
"In a web-based application, a servlet filter can be used to close the "
"<literal>Session only at the end of a user request, once the "
"rendering of the view is complete (the <emphasis>Open Session in View is closed and the transaction "
"ended before returning to the user, even when an exception occurs during "
"rendering of the view. See the Hibernate Wiki for examples of this \"Open "
"Session in View\" pattern."
msgstr ""
"在一个基于 Web 的应用中，可以利用 servlet 过滤器（filter），在用户请求"
"（request）结束、页面生成 结束时关闭 <literal>Session（这里使用了"
"<emphasis>在展示层保持打开 Session 模式（Open Session in View） "
"clause or a <literal>FetchMode.JOIN in CriteriaCommandSession Facade."
msgstr ""
"在一个拥有单独业务层的应用中，业务层必须在返回之前，为 web 层“准备”好其所需的"
"数据集合。这就意味着 业务层应该载入所有表现层/web 层所需的数据，并将这些已实"
"例化完毕的数据返回。通常，应用程序应该为 web 层所需的每个集合调用 "
"<literal>Hibernate.initialize()（这个调用必须发生咱 session 关闭之"
"前）；或者使用带有 <literal>FETCH 从句，或 FetchMode."
"JOIN</literal> 的 Hibernate 查询，事先取得所有的数据集合。如果你在应用中使用"
"了 <emphasis>Command 模式，代替 Session Facademerge() or lock() before "
"accessing uninitialized collections or other proxies. Hibernate does not, "
"and certainly <emphasis>should not, do this automatically since "
"it would introduce impromptu transaction semantics."
msgstr ""
"你也可以通过 <literal>merge() 或 lock() 方法，在"
"访问未实例化的集合（或代理）之前，为先前载入的对象绑定一个新的 "
"<literal>Session。显然，Hibernate 将不会，也不应该 method is also used to efficiently "
"retrieve subsets of a collection without needing to initialize the whole "
"collection:"
msgstr ""
"这里的 <literal>createFilter() 方法也可以被用来有效的抓取集合的部分"
"内容，而无需实例化整个集合："

#. Tag: programlisting
#: performance.xml:423
#, fuzzy, no-c-format
msgid ""
"s.createFilter( lazyCollection, \"\").setFirstResult(0).setMaxResults(10)."
"list();"
msgstr ""
"<![CDATA[s.createFilter( lazyCollection, \"\").setFirstResult(0)."
"setMaxResults(10).list();]]>"

#. Tag: title
#: performance.xml:427
#, no-c-format
msgid "Using batch fetching"
msgstr "使用批量抓取（Using batch fetching）"

#. Tag: para
#: performance.xml:429
#, no-c-format
msgid ""
"Using batch fetching, Hibernate can load several uninitialized proxies if "
"one proxy is accessed. Batch fetching is an optimization of the lazy select "
"fetching strategy. There are two ways you can configure batch fetching: on "
"the class level and the collection level."
msgstr ""
"Hibernate 可以充分有效的使用批量抓取，也就是说，如果仅一个访问代理（或集"
"合），那么 Hibernate 将不载入其他未实例化的代理。批量抓取是延迟查询抓取的优化"
"方案，你可以在两种批量抓取方案之间进行选择：在类级别和集合级别。 "

#. Tag: para
#: performance.xml:434
#, no-c-format
msgid ""
"Batch fetching for classes/entities is easier to understand. Consider the "
"following example: at runtime you have 25 <literal>Cat instances "
"loaded in a <literal>Session, and each Cat has "
"a reference to its <literal>owner, a Person. "
"The <literal>Person class is mapped with a proxy, lazy="
"\"true\"</literal>. If you now iterate through all cats and call "
"<literal>getOwner() on each, Hibernate will, by default, execute "
"25 <literal>SELECT statements to retrieve the proxied owners. You "
"can tune this behavior by specifying a <literal>batch-size in the "
"mapping of <literal>Person:"
msgstr ""
"类/实体级别的批量抓取很容易理解。假设你在运行时将需要面对下面的问题：你在一"
"个 <literal>Session 中载入了 25 个 Cat 实例，每"
"个 <literal>Cat 实例都拥有一个引用成员 owner，其"
"指向 <literal>Person，而 Person 类是代理，同时 "
"<literal>lazy=\"true\"。如果你必须遍历整个 cats 集合，对每个元素调"
"用 <literal>getOwner() 方法，Hibernate 将会默认的执行 25 次 "
"<literal>SELECT 查询， 得到其 owner 的代理对象。这时，你可以通过在"
"映射文件的 <literal>Person 属性，显式声明 batch-size]]>"

#. Tag: para
#: performance.xml:449
#, no-c-format
msgid ""
"Hibernate will now execute only three queries: the pattern is 10, 10, 5."
msgstr "随之，Hibernate 将只需要执行三次查询，分别为 10、10、 5。 "

#. Tag: para
#: performance.xml:452
#, no-c-format
msgid ""
"You can also enable batch fetching of collections. For example, if each "
"<literal>Person has a lazy collection of Cats, "
"and 10 persons are currently loaded in the <literal>Session, "
"iterating through all persons will generate 10 <literal>SELECTs, "
"one for every call to <literal>getCats(). If you enable batch "
"fetching for the <literal>cats collection in the mapping of "
"<literal>Person, Hibernate can pre-fetch collections:"
msgstr ""
"你也可以在集合级别定义批量抓取。例如，如果每个 <literal>Person 都拥"
"有一个延迟载入的 <literal>Cats 集合， 现在，Sesssion 查询，每次查询都会调用 getCats()Person 的映射定义部分，允许对 "
"<literal>cats 批量抓取，那么，Hibernate 将可以预先抓取整个集合。请"
"看例子： "

#. Tag: programlisting
#: performance.xml:461
#, fuzzy, no-c-format
msgid ""
"<class name=\"Person\">\n"
"    <set name=\"cats\" batch-size=\"3\">\n"
"        ...\n"
"    </set>\n"
"</class>"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:463
#, no-c-format
msgid ""
"With a <literal>batch-size of 3, Hibernate will load 3, 3, 3, 1 "
"collections in four <literal>SELECTs. Again, the value of the "
"attribute depends on the expected number of uninitialized collections in a "
"particular <literal>Session."
msgstr ""
"如果整个的 <literal>batch-size 是 3，那么 Hibernate 将会分四次执行 "
"<literal>SELECT 查询， 按照 3、3、3、1 的大小分别载入数据。这里的每"
"次载入的数据量还具体依赖于当前 <literal>Session 中未实例化集合的个"
"数。 "

#. Tag: para
#: performance.xml:468
#, no-c-format
msgid ""
"Batch fetching of collections is particularly useful if you have a nested "
"tree of items, i.e. the typical bill-of-materials pattern. However, a "
"<emphasis>nested set or a materialized path "
"might be a better option for read-mostly trees."
msgstr ""
"如果你的模型中有嵌套的树状结构，例如典型的帐单－原料结构（bill-of-materials "
"pattern），集合的批量抓取是非常有用的。（尽管在更多情况下对树进行读取时，"
"<emphasis>嵌套集合（nested set）或原料路径"
"（materialized path）</emphasis>可能是更好的解决方法。）"

#. Tag: title
#: performance.xml:475
#, no-c-format
msgid "Using subselect fetching"
msgstr "使用子查询抓取（Using subselect fetching）"

#. Tag: para
#: performance.xml:477
#, no-c-format
msgid ""
"If one lazy collection or single-valued proxy has to be fetched, Hibernate "
"will load all of them, re-running the original query in a subselect. This "
"works in the same way as batch-fetching but without the piecemeal loading."
msgstr ""
"假若一个延迟集合或单值代理需要抓取，Hibernate 会使用一个 subselect 重新运行原"
"来的查询，一次性读入所有的实例。这和批量抓取的实现方法是一样的，不会有破碎的"
"加载。 "

#. Tag: title
#: performance.xml:486
#, no-c-format
msgid "Fetch profiles"
msgstr "Fetch profile（抓取策略）"

#. Tag: para
#: performance.xml:488
#, fuzzy, no-c-format
msgid ""
"Another way to affect the fetching strategy for loading associated objects "
"is through something called a fetch profile, which is a named configuration "
"associated with the <interfacename>org.hibernate.SessionFactoryorg.hibernate."
"Session</interfacename>. Once enabled on a org.hibernate."
"Session</interfacename>, the fetch profile will be in affect for that "
"<interfacename>org.hibernate.Session until it is explicitly "
"disabled."
msgstr ""
"影响抓取加载相关对象的策略的另外一个方法是通过抓取配置（fetch profile），它是"
"和 <interfacename>org.hibernate.SessionFactory 相关的配置但"
"对 <interfacename>org.hibernate.Session 启用。一旦在 "
"<interfacename>org.hibernate.Session 上启用，抓取配置将对这"
"个 <interfacename>org.hibernate.Session 生效直至它被显性地禁"
"用。"

#. Tag: para
#: performance.xml:498
#, fuzzy, no-c-format
msgid ""
"So what does that mean? Well lets explain that by way of an example which "
"show the different available approaches to configure a fetch profile:"
msgstr "这是什么意思呢？让我们通过一个例子进行解释。假设我们有下列映射："

#. Tag: title
#: performance.xml:503
#, no-c-format
msgid "Specifying a fetch profile using <classname>@FetchProfile"
msgstr ""

#. Tag: programlisting
#: performance.xml:506
#, no-c-format
msgid ""
"@Entity\n"
"@FetchProfile(name = \"customer-with-orders\", fetchOverrides = {\n"
"   @FetchProfile.FetchOverride(entity = Customer.class, association = "
"\"orders\", mode = FetchMode.JOIN)\n"
"})\n"
"public class Customer {\n"
"   @Id\n"
"   @GeneratedValue\n"
"   private long id;\n"
"\n"
"   private String name;\n"
"\n"
"   private long customerNumber;\n"
"\n"
"   @OneToMany\n"
"   private Set<Order> orders;\n"
"\n"
"   // standard getter/setter\n"
"   ...\n"
"}"
msgstr ""

#. Tag: title
#: performance.xml:510
#, no-c-format
msgid ""
"Specifying a fetch profile using <literal><fetch-profile> "
"outside <literal><class> node"
msgstr ""

#. Tag: programlisting
#: performance.xml:514
#, no-c-format
msgid ""
"<hibernate-mapping>\n"
"    <class name=\"Customer\">\n"
"        ...\n"
"        <set name=\"orders\" inverse=\"true\">\n"
"            <key column=\"cust_id\"/>\n"
"            <one-to-many class=\"Order\"/>\n"
"        </set>\n"
"    </class>\n"
"    <class name=\"Order\">\n"
"        ...\n"
"    </class>\n"
"    <fetch-profile name=\"customer-with-orders\">\n"
"        <fetch entity=\"Customer\" association=\"orders\" style=\"join\"/"
">\n"
"    </fetch-profile>\n"
"</hibernate-mapping>"
msgstr ""

#. Tag: title
#: performance.xml:518
#, no-c-format
msgid ""
"Specifying a fetch profile using <literal><fetch-profile> "
"inside <literal><class> node"
msgstr ""

#. Tag: programlisting
#: performance.xml:522
#, no-c-format
msgid ""
"<hibernate-mapping>\n"
"    <class name=\"Customer\">\n"
"        ...\n"
"        <set name=\"orders\" inverse=\"true\">\n"
"            <key column=\"cust_id\"/>\n"
"            <one-to-many class=\"Order\"/>\n"
"        </set>\n"
"        <fetch-profile name=\"customer-with-orders\">\n"
"            <fetch association=\"orders\" style=\"join\"/>\n"
"        </fetch-profile>\n"
"    </class>\n"
"    <class name=\"Order\">\n"
"        ...\n"
"    </class>\n"
"</hibernate-mapping>"
msgstr ""

#. Tag: para
#: performance.xml:525
#, fuzzy, no-c-format
msgid ""
"Now normally when you get a reference to a particular customer, that "
"customer's set of orders will be lazy meaning we will not yet have loaded "
"those orders from the database. Normally this is a good thing. Now lets say "
"that you have a certain use case where it is more efficient to load the "
"customer and their orders together. One way certainly is to use \"dynamic "
"fetching\" strategies via an HQL or criteria queries. But another option is "
"to use a fetch profile to achieve that. The following code will load both "
"the customer <emphasis>andtheir orders:"
msgstr ""
"现在，当你获得某个特定客户的引用时，这个客户的订单将处于 lazy 状态，表示我们"
"暂不会从数据库里加载这些订单。这样通常没有问题。假设在某种情况下，加载客户及"
"其订单会更高效。其中一个办法当然是使用通过 HQL 或 Criteria 查询“动态抓取”的策"
"略。另外一个方法就是使用抓取配置（Fetch Profile）。你可以在映射里加入下面的内"
"容："

#. Tag: title
#: performance.xml:536
#, no-c-format
msgid "Activating a fetch profile for a given <classname>Session"
msgstr ""

#. Tag: programlisting
#: performance.xml:539
#, no-c-format
msgid ""
"Session session = ...;\n"
"session.enableFetchProfile( \"customer-with-orders\" );  // name matches "
"from mapping\n"
"Customer customer = (Customer) session.get( Customer.class, customerId );"
msgstr ""

#. Tag: para
#: performance.xml:543
#, no-c-format
msgid ""
"<classname>@FetchProfile definitions are global and it does not "
"matter on which class you place them. You can place the "
"<classname>@FetchProfile annotation either onto a class or "
"package (package-info.java). In order to define multiple fetch profiles for "
"the same class or package <classname>@FetchProfiles can be used."
msgstr ""

#. Tag: para
#: performance.xml:551
#, no-c-format
msgid ""
"Currently only join style fetch profiles are supported, but they plan is to "
"support additional styles. See <ulink url=\"http://opensource.atlassian.com/"
"projects/hibernate/browse/HHH-3414\">HHH-3414</ulink> for details."
msgstr ""
"目前只有 join 风格的抓取策略被支持，但其他风格也将被支持。更多细节请参考 "
"<ulink url=\"http://opensource.atlassian.com/projects/hibernate/browse/HHH-"
"3414\">HHH-3414</ulink>。"

#. Tag: title
#: performance.xml:558
#, no-c-format
msgid "Using lazy property fetching"
msgstr "使用延迟属性抓取（Using lazy property fetching）"

#. Tag: para
#: performance.xml:560
#, no-c-format
msgid ""
"Hibernate3 supports the lazy fetching of individual properties. This "
"optimization technique is also known as <emphasis>fetch groups. "
"Please note that this is mostly a marketing feature; optimizing row reads is "
"much more important than optimization of column reads. However, only loading "
"some properties of a class could be useful in extreme cases. For example, "
"when legacy tables have hundreds of columns and the data model cannot be "
"improved."
msgstr ""
"Hibernate3 对单独的属性支持延迟抓取，这项优化技术也被称为<emphasis>组抓取"
"（fetch groups）</emphasis>。 请注意，该技术更多的属于市场特性。在实际应用"
"中，优化行读取比优化列读取更重要。但是，仅载入类的部分属性在某些特定情况下会"
"有用，例如在原有表中拥有几百列数据、数据模型无法改动的情况下。 "

#. Tag: para
#: performance.xml:568
#, no-c-format
msgid ""
"To enable lazy property loading, set the <literal>lazy attribute "
"on your particular property mappings:"
msgstr ""
"可以在映射文件中对特定的属性设置 <literal>lazy，定义该属性为延迟载"
"入。"

#. Tag: programlisting
#: performance.xml:571
#, fuzzy, no-c-format
msgid ""
"<class name=\"Document\">\n"
"       <id name=\"id\">\n"
"        <generator class=\"native\"/>\n"
"    </id>\n"
"    <property name=\"name\" not-null=\"true\" length=\"50\"/>\n"
"    <property name=\"summary\" not-null=\"true\" length=\"200\" lazy="
"\"true\"/>\n"
"    <property name=\"text\" not-null=\"true\" length=\"2000\" lazy=\"true"
"\"/>\n"
"</class>"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:573
#, no-c-format
msgid ""
"Lazy property loading requires buildtime bytecode instrumentation. If your "
"persistent classes are not enhanced, Hibernate will ignore lazy property "
"settings and return to immediate fetching."
msgstr ""
"属性的延迟载入要求在其代码构建时加入二进制指示指令（bytecode "
"instrumentation），如果你的持久类代码中未含有这些指令， Hibernate 将会忽略这"
"些属性的延迟设置，仍然将其直接载入。 "

#. Tag: para
#: performance.xml:577
#, no-c-format
msgid "For bytecode instrumentation, use the following Ant task:"
msgstr "你可以在 Ant 的 Task 中，进行如下定义，对持久类代码加入“二进制指令。”"

#. Tag: programlisting
#: performance.xml:579
#, fuzzy, no-c-format
msgid ""
"<target name=\"instrument\" depends=\"compile\">\n"
"    <taskdef name=\"instrument\" classname=\"org.hibernate.tool."
"instrument.InstrumentTask\">\n"
"        <classpath path=\"${jar.path}\"/>\n"
"        <classpath path=\"${classes.dir}\"/>\n"
"        <classpath refid=\"lib.class.path\"/>\n"
"    </taskdef>\n"
"\n"
"    <instrument verbose=\"true\">\n"
"        <fileset dir=\"${testclasses.dir}/org/hibernate/auction/model"
"\">\n"
"            <include name=\"*.class\"/>\n"
"        </fileset>\n"
"    </instrument>\n"
"</target>"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:581
#, no-c-format
msgid ""
"A different way of avoiding unnecessary column reads, at least for read-only "
"transactions, is to use the projection features of HQL or Criteria queries. "
"This avoids the need for buildtime bytecode processing and is certainly a "
"preferred solution."
msgstr ""
"还有一种可以优化的方法，它使用 HQL 或条件查询的投影（projection）特性，可以避"
"免读取非必要的列， 这一点至少对只读事务是非常有用的。它无需在代码构建时“二进"
"制指令”处理，因此是一个更加值得选择的解决方法。 "

#. Tag: para
#: performance.xml:586
#, no-c-format
msgid ""
"You can force the usual eager fetching of properties using <literal>fetch "
"all properties</literal> in HQL."
msgstr ""
"有时你需要在 HQL 中通过<literal>抓取所有属性，强行抓取所有内容。 "

#. Tag: title
#: performance.xml:592
#, no-c-format
msgid "The Second Level Cache"
msgstr "二级缓存（The Second Level Cache）"

#. Tag: para
#: performance.xml:594
#, no-c-format
msgid ""
"A Hibernate <literal>Session is a transaction-level cache of "
"persistent data. It is possible to configure a cluster or JVM-level "
"(<literal>SessionFactory-level) cache on a class-by-class and "
"collection-by-collection basis. You can even plug in a clustered cache. Be "
"aware that caches are not aware of changes made to the persistent store by "
"another application. They can, however, be configured to regularly expire "
"cached data."
msgstr ""
"Hibernate 的 <literal>Session 在事务级别进行持久化数据的缓存操作。 "
"当然，也有可能分别为每个类（或集合），配置集群、或 JVM 级别"
"（<literal>SessionFactory 级别）的缓存。你甚至可以为之插入一个集群"
"的缓存。注意，缓存永远不知道其他应用程序对持久化仓库（数据库）可能进行的修改 "
"（即使可以将缓存数据设定为定期失效）。 "

#. Tag: para
#: performance.xml:602
#, fuzzy, no-c-format
msgid ""
"You have the option to tell Hibernate which caching implementation to use by "
"specifying the name of a class that implements <literal>org.hibernate.cache."
"CacheProvider</literal> using the property hibernate.cache."
"provider_class</literal>. Hibernate is bundled with a number of built-in "
"integrations with the open-source cache providers that are listed in <xref "
"linkend=\"cacheproviders\"/>. You can also implement your own and plug it in "
"as outlined above. Note that versions prior to Hibernate 3.2 use EhCache as "
"the default cache provider."
msgstr ""
"通过在 <literal>hibernate.cache.provider_class 属性中指定  "
"<literal>org.hibernate.cache.CacheProvider 的某个实现的类名,你可以"
"选择让 Hibernate 使用哪个缓存实现。Hibernate 打包一些开源缓存实现，提供对它们"
"的内置支持（见下表）。除此之外，你也可以实现你自己的实现，将它们插入到系统"
"中。注意，在 3.2 版本之前，默认使用 EhCache 作为缓存实现，但从 3.2 起就不再这"
"样了。 "

#. Tag: title
#: performance.xml:613
#, no-c-format
msgid "Cache Providers"
msgstr "缓存策略提供商（Cache Providers）"

#. Tag: entry
#: performance.xml:628 performance.xml:976
#, no-c-format
msgid "Cache"
msgstr "Cache"

#. Tag: entry
#: performance.xml:630
#, no-c-format
msgid "Provider class"
msgstr "Provider class"

#. Tag: entry
#: performance.xml:632
#, no-c-format
msgid "Type"
msgstr "Type"

#. Tag: entry
#: performance.xml:634
#, no-c-format
msgid "Cluster Safe"
msgstr "Cluster Safe"

#. Tag: entry
#: performance.xml:636
#, no-c-format
msgid "Query Cache Supported"
msgstr "Query Cache Supported"

#. Tag: entry
#: performance.xml:642 performance.xml:990
#, no-c-format
msgid "Hashtable (not intended for production use)"
msgstr "Hashtable （not intended for production use）"

#. Tag: literal
#: performance.xml:644
#, fuzzy, no-c-format
msgid "org.hibernate.cache.HashtableCacheProvider"
msgstr "<literal>org.hibernate.cache.HashtableCacheProvider "

#. Tag: entry
#: performance.xml:646
#, no-c-format
msgid "memory"
msgstr "memory"

#. Tag: entry
#: performance.xml:650 performance.xml:662 performance.xml:674
#: performance.xml:992 performance.xml:994 performance.xml:996
#: performance.xml:1004 performance.xml:1006 performance.xml:1008
#: performance.xml:1016 performance.xml:1018 performance.xml:1020
#: performance.xml:1028 performance.xml:1030 performance.xml:1040
#: performance.xml:1046 performance.xml:1052 performance.xml:1058
#, no-c-format
msgid "<entry>yes"
msgstr "<entry>yes"

#. Tag: entry
#: performance.xml:654 performance.xml:1002
#, no-c-format
msgid "EHCache"
msgstr "EHCache"

#. Tag: literal
#: performance.xml:656
#, fuzzy, no-c-format
msgid "org.hibernate.cache.EhCacheProvider"
msgstr "<literal>org.hibernate.cache.EhCacheProvider "

#. Tag: entry
#: performance.xml:658 performance.xml:670
#, no-c-format
msgid "memory, disk"
msgstr "memory，disk"

#. Tag: entry
#: performance.xml:666 performance.xml:1014
#, no-c-format
msgid "OSCache"
msgstr "OSCache"

#. Tag: literal
#: performance.xml:668
#, fuzzy, no-c-format
msgid "org.hibernate.cache.OSCacheProvider"
msgstr "<literal>org.hibernate.cache.OSCacheProvider "

#. Tag: entry
#: performance.xml:678 performance.xml:1026
#, no-c-format
msgid "SwarmCache"
msgstr "SwarmCache"

#. Tag: literal
#: performance.xml:680
#, fuzzy, no-c-format
msgid "org.hibernate.cache.SwarmCacheProvider"
msgstr "<literal>org.hibernate.cache.SwarmCacheProvider"

#. Tag: entry
#: performance.xml:682
#, no-c-format
msgid "clustered (ip multicast)"
msgstr "clustered (ip multicast)"

#. Tag: entry
#: performance.xml:684
#, no-c-format
msgid "yes (clustered invalidation)"
msgstr "yes (clustered invalidation)"

#. Tag: entry
#: performance.xml:690 performance.xml:1038
#, no-c-format
msgid "JBoss Cache 1.x"
msgstr "JBoss Cache 1.x"

#. Tag: literal
#: performance.xml:692
#, fuzzy, no-c-format
msgid "org.hibernate.cache.TreeCacheProvider"
msgstr "<literal>org.hibernate.cache.TreeCacheProvider "

#. Tag: entry
#: performance.xml:694 performance.xml:706
#, no-c-format
msgid "clustered (ip multicast), transactional"
msgstr "clustered (ip multicast), transactional"

#. Tag: entry
#: performance.xml:696
#, no-c-format
msgid "yes (replication)"
msgstr "yes (replication)"

#. Tag: entry
#: performance.xml:698 performance.xml:710
#, no-c-format
msgid "yes (clock sync req.)"
msgstr "yes (clock sync req.)"

#. Tag: entry
#: performance.xml:702 performance.xml:1050
#, no-c-format
msgid "JBoss Cache 2"
msgstr "JBoss Cache 2"

#. Tag: literal
#: performance.xml:704
#, fuzzy, no-c-format
msgid "org.hibernate.cache.jbc.JBossCacheRegionFactory"
msgstr "<literal>org.hibernate.cache.jbc.JBossCacheRegionFactory"

#. Tag: entry
#: performance.xml:708
#, no-c-format
msgid "yes (replication or invalidation)"
msgstr "yes (replication or invalidation)"

#. Tag: title
#: performance.xml:717
#, no-c-format
msgid "Cache mappings"
msgstr "缓存映射（Cache mappings）"

#. Tag: para
#: performance.xml:719
#, no-c-format
msgid ""
"As we have done in previous chapters we are looking at the two different "
"possibiltites to configure caching. First configuration via annotations and "
"then via Hibernate mapping files."
msgstr ""

#. Tag: para
#: performance.xml:723
#, no-c-format
msgid ""
"By default, entities are not part of the second level cache and we recommend "
"you to stick to this setting. However, you can override this by setting the "
"<literal>shared-cache-mode element in your persistence."
"xml</filename> file or by using the javax.persistence.sharedCache."
"mode </literal>property in your configuration. The following values are "
"possible:"
msgstr ""

#. Tag: para
#: performance.xml:732
#, no-c-format
msgid ""
"<literal>ENABLE_SELECTIVE (Default and recommended value): "
"entities are not cached unless explicitly marked as cacheable."
msgstr ""

#. Tag: para
#: performance.xml:738
#, no-c-format
msgid ""
"<literal>DISABLE_SELECTIVE: entities are cached unless explicitly "
"marked as not cacheable."
msgstr ""

#. Tag: para
#: performance.xml:743
#, no-c-format
msgid ""
"<literal>ALL: all entities are always cached even if marked as non "
"cacheable."
msgstr ""

#. Tag: para
#: performance.xml:748
#, no-c-format
msgid ""
"<literal>NONE: no entity are cached even if marked as cacheable. "
"This option can make sense to disable second-level cache altogether."
msgstr ""

#. Tag: para
#: performance.xml:754
#, no-c-format
msgid ""
"The cache concurrency strategy used by default can be set globaly via the "
"<literal>hibernate.cache.default_cache_concurrency_strategy "
"configuration property. The values for this property are:"
msgstr ""

#. Tag: literal
#: performance.xml:761
#, fuzzy, no-c-format
msgid "<literal>read-only"
msgstr "条件查询"

#. Tag: literal
#: performance.xml:765
#, fuzzy, no-c-format
msgid "<literal>read-write"
msgstr "条件查询"

#. Tag: literal
#: performance.xml:769
#, fuzzy, no-c-format
msgid "<literal>nonstrict-read-write"
msgstr "nonstrict-read-write"

#. Tag: literal
#: performance.xml:773
#, fuzzy, no-c-format
msgid "<literal>transactional"
msgstr "条件查询"

#. Tag: para
#: performance.xml:778
#, no-c-format
msgid ""
"It is recommended to define the cache concurrency strategy per entity rather "
"than using a global one. Use the <classname>@org.hibernate.annotations."
"Cache</classname> annotation for that."
msgstr ""

#. Tag: title
#: performance.xml:785
#, no-c-format
msgid ""
"Definition of cache concurrency strategy via <classname>@Cache"
msgstr ""

#. Tag: programlisting
#: performance.xml:788
#, no-c-format
msgid ""
"@Entity \n"
"@Cacheable\n"
"@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)\n"
"public class Forest { ... }"
msgstr ""

#. Tag: para
#: performance.xml:791
#, no-c-format
msgid ""
"Hibernate also let's you cache the content of a collection or the "
"identifiers if the collection contains other entities. Use the "
"<classname>@Cache annotation on the collection property."
msgstr ""

#. Tag: title
#: performance.xml:797
#, fuzzy, no-c-format
msgid "Caching collections using annotations"
msgstr "实例化集合和代理（Initializing collections and proxies）"

#. Tag: programlisting
#: performance.xml:799
#, no-c-format
msgid ""
"@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)\n"
"@JoinColumn(name=\"CUST_ID\")\n"
"@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)\n"
"public SortedSet<Ticket> getTickets() {\n"
"    return tickets;\n"
"}"
msgstr ""

#. Tag: para
#: performance.xml:802
#, no-c-format
msgid ""
"shows the<literal> @org.hibernate.annotations.Cache annotations "
"with its attributes. It allows you to define the caching strategy and region "
"of a given second level cache."
msgstr ""

#. Tag: title
#: performance.xml:808
#, no-c-format
msgid "<classname>@Cache annotation with attributes"
msgstr ""

#. Tag: programlisting
#: performance.xml:820
#, no-c-format
msgid ""
"@Cache(\n"
"    CacheConcurrencyStrategy usage();\n"
"    String region() default \"\";\n"
"    String include() default \"all\";\n"
")"
msgstr ""

#. Tag: para
#: performance.xml:824
#, no-c-format
msgid ""
"usage: the given cache concurrency strategy (NONE, READ_ONLY, "
"NONSTRICT_READ_WRITE, READ_WRITE, TRANSACTIONAL)"
msgstr ""

#. Tag: para
#: performance.xml:830
#, no-c-format
msgid ""
"region (optional): the cache region (default to the fqcn of the class or the "
"fq role name of the collection)"
msgstr ""

#. Tag: para
#: performance.xml:835
#, no-c-format
msgid ""
"<literal>include (optional): all to include all properties, non-"
"lazy to only include non lazy properties (default all)."
msgstr ""

#. Tag: para
#: performance.xml:843
#, no-c-format
msgid ""
"Let's now take a look at Hibernate mapping files. There the <literal><"
"cache></literal> element of a class or collection mapping is used to "
"configure the second level cache. Looking at <xref linkend=\"example-"
"hibernate-cache-mapping-element\"/> the parallels to anotations is obvious."
msgstr ""

#. Tag: title
#: performance.xml:850
#, no-c-format
msgid "The Hibernate <literal><cache> mapping element"
msgstr ""

#. Tag: programlisting
#: performance.xml:862
#, fuzzy, no-c-format
msgid ""
"<cache\n"
"    usage=\"transactional|read-write|nonstrict-read-write|read-only\"\n"
"    region=\"RegionName\"\n"
"    include=\"all|non-lazy\"\n"
"/>"
msgstr ""
"<![CDATA["

#. Tag: para
#: performance.xml:866
#, no-c-format
msgid ""
"<literal>usage (required) specifies the caching strategy: "
"<literal>transactional, read-write, "
"<literal>nonstrict-read-write or read-only"
msgstr ""
"<literal>usage（必须）说明了缓存的策略：transactionalread-write、nonstrict-read-writeread-only。"

#. Tag: para
#: performance.xml:874
#, no-c-format
msgid ""
"<literal>region (optional: defaults to the class or collection "
"role name): specifies the name of the second level cache region"
msgstr ""
"<literal>region （可选，默认为类或者集合的名字（class or "
"collection role name）） 指定第二级缓存的区域名（name of the second level "
"cache region） "

#. Tag: para
#: performance.xml:880
#, no-c-format
msgid ""
"<literal>include (optional: defaults to all) "
"<literal>non-lazy: specifies that properties of the entity mapped "
"with <literal>lazy=\"true\" cannot be cached when attribute-level "
"lazy fetching is enabled"
msgstr ""
"<literal>include（可选,默认为 all） "
"<literal>non-lazy 当属性级延迟抓取打开时，标记为 lazy="
"\"true\"</literal> 的实体的属性可能无法被缓存 "

#. Tag: para
#: performance.xml:890
#, fuzzy, no-c-format
msgid ""
"Alternatively to <literal><cache>, you can use <"
"class-cache></literal> and <collection-cache> "
"elements in <literal>hibernate.cfg.xml."
msgstr ""
"另外（首选?），你可以在<literal>hibernate.cfg.xml 中指定 "
"<literal><class-cache> 和 <collection-cache> cache can be used. This is the "
"simplest and optimal performing strategy. It is even safe for use in a "
"cluster."
msgstr ""
"如果你的应用程序只需读取一个持久化类的实例，而无需对其修改， 那么就可以对其进"
"行<literal>只读 缓存。这是最简单，也是实用性最好的方法。甚至在集群"
"中，它也能完美地运作。 "

#. Tag: title
#: performance.xml:909
#, no-c-format
msgid "Strategy: read/write"
msgstr "策略：读写/缓存（Strategy：read/write）"

#. Tag: para
#: performance.xml:911
#, no-c-format
msgid ""
"If the application needs to update data, a <literal>read-write "
"cache might be appropriate. This cache strategy should never be used if "
"serializable transaction isolation level is required. If the cache is used "
"in a JTA environment, you must specify the property <literal>hibernate."
"transaction.manager_lookup_class</literal> and naming a strategy for "
"obtaining the JTA <literal>TransactionManager. In other "
"environments, you should ensure that the transaction is completed when "
"<literal>Session.close() or Session.disconnect() support locking."
msgstr ""
"如果应用程序需要更新数据，那么使用<literal>读/写缓存 比较合适。 如"
"果应用程序要求“序列化事务”的隔离级别（serializable transaction isolation "
"level），那么就决不能使用这种缓存策略。 如果在 JTA 环境中使用缓存，你必须指"
"定 <literal>hibernate.transaction.manager_lookup_class 属性的值， "
"通过它，Hibernate 才能知道该应用程序中 JTA 的<literal>TransactionManagerSession.close()Session.disconnect() 调用前， 整个事务已经结"
"束。 如果你想在集群环境中使用此策略，你必须保证底层的缓存实现支持锁定"
"（locking）。Hibernate 内置的缓存策略并不支持锁定功能。 "

#. Tag: title
#: performance.xml:927
#, no-c-format
msgid "Strategy: nonstrict read/write"
msgstr "策略：非严格读/写缓存（Strategy：nonstrict read/write）"

#. Tag: para
#: performance.xml:929
#, no-c-format
msgid ""
"If the application only occasionally needs to update data (i.e. if it is "
"extremely unlikely that two transactions would try to update the same item "
"simultaneously), and strict transaction isolation is not required, a "
"<literal>nonstrict-read-write cache might be appropriate. If the "
"cache is used in a JTA environment, you must specify <literal>hibernate."
"transaction.manager_lookup_class</literal>. In other environments, you "
"should ensure that the transaction is completed when <literal>Session.close()"
"</literal> or Session.disconnect() is called."
msgstr ""
"如果应用程序只偶尔需要更新数据（也就是说，两个事务同时更新同一记录的情况很不"
"常见），也不需要十分严格的事务隔离，那么比较适合使用<literal>非严格读/写缓存"
"</literal>策略。如果在 JTA 环境中使用该策略，你必须为其指定 "
"<literal>hibernate.transaction.manager_lookup_class 属性的值，在其"
"它环境中，你必须保证在<literal>Session.close()、或 "
"<literal>Session.disconnect() 调用前，整个事务已经结束。 "

#. Tag: title
#: performance.xml:941
#, no-c-format
msgid "Strategy: transactional"
msgstr "策略：事务缓存（transactional）"

#. Tag: para
#: performance.xml:943
#, no-c-format
msgid ""
"The <literal>transactional cache strategy provides support for "
"fully transactional cache providers such as JBoss TreeCache. Such a cache "
"can only be used in a JTA environment and you must specify "
"<literal>hibernate.transaction.manager_lookup_class."
msgstr ""
"Hibernate 的<literal>事务缓存策略提供了全事务的缓存支持，例如对 "
"JBoss TreeCache 的支持。这样的缓存只能用于 JTA 环境中，你必须指定为其  "
"<literal>hibernate.transaction.manager_lookup_class 属性。 "

#. Tag: title
#: performance.xml:950
#, no-c-format
msgid "Cache-provider/concurrency-strategy compatibility"
msgstr "各种缓存提供商/缓存并发策略的兼容性"

#. Tag: para
#: performance.xml:953
#, no-c-format
msgid ""
"None of the cache providers support all of the cache concurrency strategies."
msgstr ""
"没有一种缓存提供商能够支持上列的所有缓存并发策略。下表中列出了各种提供器、及"
"其各自适用的并发策略。 "

#. Tag: para
#: performance.xml:957
#, no-c-format
msgid ""
"The following table shows which providers are compatible with which "
"concurrency strategies."
msgstr ""
"没有一种缓存提供商能够支持上列的所有缓存并发策略。下表中列出了各种提供器、及"
"其各自适用的并发策略。 "

#. Tag: title
#: performance.xml:961
#, no-c-format
msgid "Cache Concurrency Strategy Support"
msgstr ""
"各种缓存提供商对缓存并发策略的支持情况（Cache Concurrency Strategy Support）"

#. Tag: entry
#: performance.xml:978
#, fuzzy, no-c-format
msgid "<entry>read-only"
msgstr "<entry>yes"

#. Tag: entry
#: performance.xml:980
#, fuzzy, no-c-format
msgid "<entry>nonstrict-read-write"
msgstr "nonstrict-read-write"

#. Tag: entry
#: performance.xml:982
#, fuzzy, no-c-format
msgid "<entry>read-write"
msgstr "<entry>yes"

#. Tag: entry
#: performance.xml:984
#, fuzzy, no-c-format
msgid "<entry>transactional"
msgstr "<entry>yes"

#. Tag: title
#: performance.xml:1067
#, no-c-format
msgid "Managing the caches"
msgstr "管理缓存（Managing the caches）"

#. Tag: para
#: performance.xml:1069
#, no-c-format
msgid ""
"Whenever you pass an object to <literal>save(), update()saveOrUpdate(), and whenever you retrieve an "
"object using <literal>load(), get(), "
"<literal>list(), iterate() or scroll()"
"</literal>, that object is added to the internal cache of the "
"<literal>Session."
msgstr ""
"无论何时，当你给 <literal>save()、update() 或  "
"<literal>saveOrUpdate() 方法传递一个对象时，或使用 load()"
"</literal>、get()、list()、"
"<literal>iterate() 或 scroll() 方法获得一个对象"
"时，该对象都将被加入到 <literal>Session 的内部缓存中。 "

#. Tag: para
#: performance.xml:1076
#, no-c-format
msgid ""
"When <literal>flush() is subsequently called, the state of that "
"object will be synchronized with the database. If you do not want this "
"synchronization to occur, or if you are processing a huge number of objects "
"and need to manage memory efficiently, the <literal>evict() method "
"can be used to remove the object and its collections from the first-level "
"cache."
msgstr ""
"当随后 flush() 方法被调用时，对象的状态会和数据库取得同步。如果你不希望此同步"
"操作发生，或者你正处理大量对象、需要对有效管理内存时，你可以调用 "
"<literal>evict() 方法，从一级缓存中去掉这些对象及其集合。 "

#. Tag: title
#: performance.xml:1084
#, no-c-format
msgid ""
"Explcitly evicting a cached instance from the first level cache using "
"<methodname>Session.evict()"
msgstr ""

#. Tag: programlisting
#: performance.xml:1087
#, fuzzy, no-c-format
msgid ""
"ScrollableResult cats = sess.createQuery(\"from Cat as cat\").scroll(); //a "
"huge result set\n"
"while ( cats.next() ) {\n"
"    Cat cat = (Cat) cats.get(0);\n"
"    doSomethingWithACat(cat);\n"
"    sess.evict(cat);\n"
"}"
msgstr ""
"<![CDATA[ScrollableResult cats = sess.createQuery(\"from Cat as cat\").scroll"
"(); //a huge result set\n"
"while ( cats.next() ) {\n"
"    Cat cat = (Cat) cats.get(0);\n"
"    doSomethingWithACat(cat);\n"
"    sess.evict(cat);\n"
"}]]>"

#. Tag: para
#: performance.xml:1090
#, no-c-format
msgid ""
"The <literal>Session also provides a contains() "
"method to determine if an instance belongs to the session cache."
msgstr ""
"Session 还提供了一个 <literal>contains() 方法，用来判断某个实例是否"
"处于当前 session 的缓存中。"

#. Tag: para
#: performance.xml:1094
#, no-c-format
msgid ""
"To evict all objects from the session cache, call <literal>Session.clear() for evicting the cached state of an "
"instance, entire class, collection instance or entire collection role."
msgstr ""
"对于二级缓存来说，在 <literal>SessionFactory 中定义了许多方法，清除"
"缓存中实例、整个类、集合实例或者整个集合。"

#. Tag: title
#: performance.xml:1103
#, no-c-format
msgid ""
"Second-level cache eviction via <methodname>SessionFactoty.evict() SessionFacyory.evictCollection()"
msgstr ""

#. Tag: programlisting
#: performance.xml:1107
#, fuzzy, no-c-format
msgid ""
"sessionFactory.evict(Cat.class, catId); //evict a particular Cat\n"
"sessionFactory.evict(Cat.class);  //evict all Cats\n"
"sessionFactory.evictCollection(\"Cat.kittens\", catId); //evict a particular "
"collection of kittens\n"
"sessionFactory.evictCollection(\"Cat.kittens\"); //evict all kitten "
"collections"
msgstr ""
"<![CDATA[sessionFactory.evict(Cat.class, catId); //evict a particular Cat\n"
"sessionFactory.evict(Cat.class);  //evict all Cats\n"
"sessionFactory.evictCollection(\"Cat.kittens\", catId); //evict a particular "
"collection of kittens\n"
"sessionFactory.evictCollection(\"Cat.kittens\"); //evict all kitten "
"collections]]>"

#. Tag: para
#: performance.xml:1110
#, no-c-format
msgid ""
"The <literal>CacheMode controls how a particular session interacts "
"with the second-level cache:"
msgstr ""
"<literal>CacheMode 参数用于控制具体的 Session 如何与二级缓存进行交"
"互。 "

#. Tag: para
#: performance.xml:1115
#, no-c-format
msgid ""
"<literal>CacheMode.NORMAL: will read items from and write items to "
"the second-level cache"
msgstr "<literal>CacheMode.NORMAL：从二级缓存中读、写数据。"

#. Tag: para
#: performance.xml:1120
#, no-c-format
msgid ""
"<literal>CacheMode.GET: will read items from the second-level "
"cache. Do not write to the second-level cache except when updating data"
msgstr ""
"<literal>CacheMode.GET：从二级缓存中读取数据，仅在数据更新时对二级"
"缓存写数据。"

#. Tag: para
#: performance.xml:1126
#, no-c-format
msgid ""
"<literal>CacheMode.PUT: will write items to the second-level "
"cache. Do not read from the second-level cache"
msgstr ""
"<literal>CacheMode.PUT：仅向二级缓存写数据，但不从二级缓存中读数"
"据。"

#. Tag: para
#: performance.xml:1131
#, no-c-format
msgid ""
"<literal>CacheMode.REFRESH: will write items to the second-level "
"cache. Do not read from the second-level cache. Bypass the effect of "
"<literal>hibernate.cache.use_minimal_puts forcing a refresh of the "
"second-level cache for all items read from the database"
msgstr ""
"<literal>CacheMode.REFRESH：仅向二级缓存写数据，但不从二级缓存中读"
"数据。通过 <literal>hibernate.cache.use_minimal_puts 的设置，强制二"
"级缓存从数据库中读取数据，刷新缓存内容。"

#. Tag: para
#: performance.xml:1139
#, no-c-format
msgid ""
"To browse the contents of a second-level or query cache region, use the "
"<literal>Statistics API:"
msgstr ""
"如若需要查看二级缓存或查询缓存区域的内容，你可以使用<literal>统计"
"（Statistics）</literal> API。"

#. Tag: title
#: performance.xml:1143
#, fuzzy, no-c-format
msgid ""
"Browsing the second-level cache entries via the <classname>Statistics, holding the "
"cached query results"
msgstr ""
"<classname>org.hibernate.cache.StandardQueryCache，保存缓存的查询"
"结果"

#. Tag: para
#: performance.xml:1186
#, no-c-format
msgid ""
"<classname>org.hibernate.cache.UpdateTimestampsCache, holding "
"timestamps of the most recent updates to queryable tables. These are used to "
"validate the results as they are served from the query cache."
msgstr ""
"<classname>org.hibernate.cache.UpdateTimestampsCache，保存对可查"
"询表的最近更新的时间戳。它们用于检验查询结果。"

#. Tag: para
#: performance.xml:1194
#, fuzzy, no-c-format
msgid ""
"If you configure your underlying cache implementation to use expiry or "
"timeouts is very important that the cache timeout of the underlying cache "
"region for the UpdateTimestampsCache be set to a higher value than the "
"timeouts of any of the query caches. In fact, we recommend that the the "
"UpdateTimestampsCache region not be configured for expiry at all. Note, in "
"particular, that an LRU cache expiry policy is never appropriate."
msgstr ""
"如果你配置底层缓存实现来使用过期（expiry）或超时（timeout），把用于 "
"UpdateTimestampsCache 的底层缓存 region 的缓存超时时间设置为比任何查询缓存的"
"超时时间更长的值是非常重要的。事实上，我们推荐根本不把 UpdateTimestampsCache "
"region 用于 expiry。请注意，特别是 LRU 缓存 expiry 策略总是不合适的。"

#. Tag: para
#: performance.xml:1203
#, no-c-format
msgid ""
"As mentioned above, most queries do not benefit from caching or their "
"results. So by default, individual queries are not cached even after "
"enabling query caching. To enable results caching for a particular query, "
"call <literal>org.hibernate.Query.setCacheable(true). This call "
"allows the query to look for existing cache results or add its results to "
"the cache when it is executed."
msgstr ""
"如上面所提及的，绝大多数的查询并不能从查询缓存中受益，所以 Hibernate 默认是不"
"进行查询缓存的。如若需要进行缓存，请调用 <literal>org.hibernate.Query."
"setCacheable（true）</literal>方法。这个调用会让查询在执行过程中时先从缓存中"
"查找结果，并将自己的结果集放到缓存中去。 "

#. Tag: para
#: performance.xml:1211
#, no-c-format
msgid ""
"The query cache does not cache the state of the actual entities in the "
"cache; it caches only identifier values and results of value type. For this "
"reaso, the query cache should always be used in conjunction with the second-"
"level cache for those entities expected to be cached as part of a query "
"result cache (just as with collection caching)."
msgstr ""
"查询缓存不会缓存缓存中实际实体的状态；它只缓存标识符值和值类型的结果。出于这"
"个原因，对于那些作为查询结果缓存的一部分（和集合缓存一样）进行缓存的实体，查"
"询缓存应该和二级缓存一起使用。"

#. Tag: title
#: performance.xml:1221
#, no-c-format
msgid "Query cache regions"
msgstr "查询缓存区"

#. Tag: para
#: performance.xml:1223
#, no-c-format
msgid ""
"If you require fine-grained control over query cache expiration policies, "
"you can specify a named cache region for a particular query by calling "
"<literal>Query.setCacheRegion()."
msgstr ""
"如果你要对查询缓存的失效政策进行精确的控制，你必须调用 <literal>Query."
"setCacheRegion()</literal> 方法，为每个查询指定其命名的缓存区域。 "

#. Tag: programlisting
#: performance.xml:1227
#, fuzzy, no-c-format
msgid ""
"List blogs = sess.createQuery(\"from Blog blog where blog.blogger = :blogger"
"\")\n"
"        .setEntity(\"blogger\", blogger)\n"
"        .setMaxResults(15)\n"
"        .setCacheable(true)\n"
"        .setCacheRegion(\"frontpages\")\n"
"        .list();"
msgstr ""
"<![CDATA[List blogs = sess.createQuery(\"from Blog blog where blog.blogger "
"= :blogger\")\n"
"    .setEntity(\"blogger\", blogger)\n"
"    .setMaxResults(15)\n"
"    .setCacheable(true)\n"
"    .setCacheRegion(\"frontpages\")\n"
"    .list();]]>"

#. Tag: para
#: performance.xml:1229
#, no-c-format
msgid ""
"If you want to force the query cache to refresh one of its regions "
"(disregard any cached results it finds there) you can use <literal>org."
"hibernate.Query.setCacheMode(CacheMode.REFRESH)</literal>. In conjunction "
"with the region you have defined for the given query, Hibernate will "
"selectively force the results cached in that particular region to be "
"refreshed. This is particularly useful in cases where underlying data may "
"have been updated via a separate process and is a far more efficient "
"alternative to bulk eviction of the region via <literal>org.hibernate."
"SessionFactory.evictQueries()</literal>."
msgstr ""
"如果查询需要强行刷新其查询缓存区域，那么你应该调用 <literal>org.hibernate."
"Query.setCacheMode（CacheMode.REFRESH）</literal>方法。 这对在其他进程中修改"
"底层数据（例如，不通过Hibernate修改数据），或对那些需要选择性更新特定查询结果"
"集的情况特别有用。这是对 <literal>org.hibernate.SessionFactory.evictQueries()"
"</literal> 的更为有效的替代方案，同样可以清除查询缓存区域。"

#. Tag: title
#: performance.xml:1242
#, no-c-format
msgid "Understanding Collection performance"
msgstr "理解集合性能（Understanding Collection performance）"

#. Tag: para
#: performance.xml:1244
#, no-c-format
msgid ""
"In the previous sections we have covered collections and their applications. "
"In this section we explore some more issues in relation to collections at "
"runtime."
msgstr ""
"在前面的章节里我们已经讨论了集合和相关应用程序。在本节我么将探索运行时集合的"
"更多问题。"

#. Tag: title
#: performance.xml:1249
#, no-c-format
msgid "Taxonomy"
msgstr "分类（Taxonomy）"

#. Tag: para
#: performance.xml:1251
#, no-c-format
msgid "Hibernate defines three basic kinds of collections:"
msgstr "Hibernate 定义了三种基本类型的集合："

#. Tag: para
#: performance.xml:1255
#, no-c-format
msgid "collections of values"
msgstr "值数据集合"

#. Tag: para
#: performance.xml:1259
#, no-c-format
msgid "one-to-many associations"
msgstr "一对多关联（One-to-many Associations） "

#. Tag: para
#: performance.xml:1263
#, no-c-format
msgid "many-to-many associations"
msgstr "多对多关联 "

#. Tag: para
#: performance.xml:1267
#, no-c-format
msgid ""
"This classification distinguishes the various table and foreign key "
"relationships but does not tell us quite everything we need to know about "
"the relational model. To fully understand the relational structure and "
"performance characteristics, we must also consider the structure of the "
"primary key that is used by Hibernate to update or delete collection rows. "
"This suggests the following classification:"
msgstr ""
"这个分类是区分了不同的表和外键关系类型，但是它没有告诉我们关系模型的所有内"
"容。 要完全理解他们的关系结构和性能特点，我们必须同时考虑“用于 Hibernate 更新"
"或删除集合行数据的主键的结构”。因此得到了如下的分类："

#. Tag: para
#: performance.xml:1276
#, no-c-format
msgid "indexed collections"
msgstr "有序集合类"

#. Tag: para
#: performance.xml:1280
#, no-c-format
msgid "sets"
msgstr "集合（sets）"

#. Tag: para
#: performance.xml:1284
#, no-c-format
msgid "bags"
msgstr "包（bags）"

#. Tag: para
#: performance.xml:1288
#, no-c-format
msgid ""
"All indexed collections (maps, lists, and arrays) have a primary key "
"consisting of the <literal><key> and <index><index> 组成的主键。这种情况下集合类的更"
"新是非常高效的 — 主键已经被有效的索引，因此当 Hibernate 试图更新或删除一行"
"时，可以迅速找到该行数据。 "

#. Tag: para
#: performance.xml:1295
#, no-c-format
msgid ""
"Sets have a primary key consisting of <literal><key> and "
"element columns. This can be less efficient for some types of collection "
"element, particularly composite elements or large text or binary fields, as "
"the database may not be able to index a complex primary key as efficiently. "
"However, for one-to-many or many-to-many associations, particularly in the "
"case of synthetic identifiers, it is likely to be just as efficient. If you "
"want <literal>SchemaExport to actually create the primary key of a "
"<literal><set>, you must declare all columns as not-"
"null=\"true\"</literal>."
msgstr ""
"集合（sets）的主键由 <literal><key> 和其他元素字段构成。对于"
"有些元素类型来说，这很低效，特别是组合元素或者大文本、大二进制字段；数据库可"
"能无法有效的对复杂的主键进行索引。另一方面，对于一对多、多对多关联，特别是合"
"成的标识符来说，集合也可以达到同样的高效性能。（ 附注：如果你希望 "
"<literal>SchemaExport 为你的 <set> 创建主"
"键，你必须把所有的字段都声明为 <literal>not-null=\"true\"。） "

#. Tag: para
#: performance.xml:1306
#, no-c-format
msgid ""
"<literal><idbag> mappings define a surrogate key, so they "
"are efficient to update. In fact, they are the best case."
msgstr ""
"<literal><idbag> 映射定义了代理键，因此它总是可以很高效的被更"
"新。事实上，<literal><idbag> 拥有着最好的性能表现。 "

#. Tag: para
#: performance.xml:1309
#, no-c-format
msgid ""
"Bags are the worst case since they permit duplicate element values and, as "
"they have no index column, no primary key can be defined. Hibernate has no "
"way of distinguishing between duplicate rows. Hibernate resolves this "
"problem by completely removing in a single <literal>DELETE and "
"recreating the collection whenever it changes. This can be inefficient."
msgstr ""
"Bag 是最差的。因为 bag 允许重复的元素值，也没有索引字段，因此不可能定义主"
"键。 Hibernate 无法判断出重复的行。当这种集合被更改时，Hibernate 将会先完整地"
"移除 （通过一个（in a single <literal>DELETE））整个集合，然后再重"
"新创建整个集合。因此 Bag 是非常低效的。 "

#. Tag: para
#: performance.xml:1316
#, no-c-format
msgid ""
"For a one-to-many association, the \"primary key\" may not be the physical "
"primary key of the database table. Even in this case, the above "
"classification is still useful. It reflects how Hibernate \"locates\" "
"individual rows of the collection."
msgstr ""
"请注意：对于一对多关联来说，“主键”很可能并不是数据库表的物理主键。但就算在此"
"情况下，上面的分类仍然是有用的。（它仍然反映了 Hibernate 在集合的各数据行中是"
"如何进行“定位”的。） "

#. Tag: title
#: performance.xml:1323
#, no-c-format
msgid ""
"Lists, maps, idbags and sets are the most efficient collections to update"
msgstr "Lists，maps 和 sets 用于更新效率最高"

#. Tag: para
#: performance.xml:1326
#, no-c-format
msgid ""
"From the discussion above, it should be clear that indexed collections and "
"sets allow the most efficient operation in terms of adding, removing and "
"updating elements."
msgstr ""
"根据我们上面的讨论，显然有序集合类型和大多数 set 都可以在增加、删除、修改元素"
"中拥有最好的性能。 "

#. Tag: para
#: performance.xml:1330
#, no-c-format
msgid ""
"There is, arguably, one more advantage that indexed collections have over "
"sets for many-to-many associations or collections of values. Because of the "
"structure of a <literal>Set, Hibernate does not UPDATESetINSERT and DELETE 的内在结构， 如果“改变”了一个元素，Hibernate 并不"
"会<literal>更新（UPDATE）这一行。对于 Set 来说，"
"只有在<literal>插入（INSERT）和删除（DELETE） 操"
"作时“改变”才有效。再次强调：这段讨论对“一对多关联”并不适用。 "

#. Tag: para
#: performance.xml:1338
#, no-c-format
msgid ""
"After observing that arrays cannot be lazy, you can conclude that lists, "
"maps and idbags are the most performant (non-inverse) collection types, with "
"sets not far behind. You can expect sets to be the most common kind of "
"collection in Hibernate applications. This is because the \"set\" semantics "
"are most natural in the relational model."
msgstr ""
"注意到数组无法延迟载入，我们可以得出结论，list，map 和 idbags 是最高效的（非"
"反向）集合类型，set 则紧随其后。 在 Hibernate 中，set 应该时最通用的集合类"
"型，这时因为“set”的语义在关系模型中是最自然的。 "

#. Tag: para
#: performance.xml:1344
#, no-c-format
msgid ""
"However, in well-designed Hibernate domain models, most collections are in "
"fact one-to-many associations with <literal>inverse=\"true\". For "
"these associations, the update is handled by the many-to-one end of the "
"association, and so considerations of collection update performance simply "
"do not apply."
msgstr ""
"但是，在设计良好的 Hibernate 领域模型中，我们通常可以看到更多的集合事实上是带"
"有  <literal>inverse=\"true\" 的一对多的关联。对于这些关联，更新操"
"作将会在多对一的这一端进行处理。因此对于此类情况，无需考虑其集合的更新性能。 "

#. Tag: title
#: performance.xml:1352
#, no-c-format
msgid "Bags and lists are the most efficient inverse collections"
msgstr "Bag 和 list 是反向集合类中效率最高的"

#. Tag: para
#: performance.xml:1354
#, no-c-format
msgid ""
"There is a particular case, however, in which bags, and also lists, are much "
"more performant than sets. For a collection with <literal>inverse=\"true\", "
"<literal>Collection.add() or Collection.addAll()List. This "
"can make the following common code much faster:"
msgstr ""
"在把 bag 扔进水沟之前，你必须了解，在一种情况下，bag 的性能（包括list）要比 "
"set 高得多：对于指明了 <literal>inverse=\"true\" 的集合类（比如说，"
"标准的双向的一对多关联），我们可以在未初始化（fetch）包元素的情况下直接向 "
"bag 或 list 添加新元素！ 这是因为 <literal>Collection.add()）或者 "
"<literal>Collection.addAll() 方法对 bag 或者 List 总是返回 true（这"
"点与与 Set 不同）。因此对于下面的相同代码来说，速度会快得多。 "

#. Tag: programlisting
#: performance.xml:1365
#, fuzzy, no-c-format
msgid ""
"Parent p = (Parent) sess.load(Parent.class, id);\n"
"Child c = new Child();\n"
"c.setParent(p);\n"
"p.getChildren().add(c);  //no need to fetch the collection!\n"
"sess.flush();"
msgstr ""
"<![CDATA[Parent p = (Parent) sess.load(Parent.class, id);\n"
"Child c = new Child();\n"
"c.setParent(p);\n"
"p.getChildren().add(c);  //no need to fetch the collection!\n"
"sess.flush();]]>"

#. Tag: title
#: performance.xml:1369
#, no-c-format
msgid "One shot delete"
msgstr "一次性删除（One shot delete）"

#. Tag: para
#: performance.xml:1371
#, no-c-format
msgid ""
"Deleting collection elements one by one can sometimes be extremely "
"inefficient. Hibernate knows not to do that in the case of an newly-empty "
"collection (if you called <literal>list.clear(), for example). In "
"this case, Hibernate will issue a single <literal>DELETE."
msgstr ""
"偶尔的，逐个删除集合类中的元素是相当低效的。Hibernate 并没那么笨，如果你想要"
"把整个集合都删除（比如说调用 list.clear()），Hibernate 只需要一个 DELETE 就搞"
"定了。 "

#. Tag: para
#: performance.xml:1377
#, no-c-format
msgid ""
"Suppose you added a single element to a collection of size twenty and then "
"remove two elements. Hibernate will issue one <literal>INSERT "
"statement and two <literal>DELETE statements, unless the "
"collection is a bag. This is certainly desirable."
msgstr ""
"假设我们在一个长度为20的集合类中新增加了一个元素，然后再删除两个。Hibernate "
"会安排一条 <literal>INSERT 语句和两条 DELETE 语"
"句（除非集合类是一个 bag）。这当然是令人满意的。 "

#. Tag: para
#: performance.xml:1383
#, no-c-format
msgid ""
"However, suppose that we remove eighteen elements, leaving two and then add "
"thee new elements. There are two possible ways to proceed"
msgstr ""
"但是，假设我们删除了 18 个数据，只剩下 2 个，然后新增 3 个。则有两种处理方"
"式："

#. Tag: para
#: performance.xml:1389
#, no-c-format
msgid "delete eighteen rows one by one and then insert three rows"
msgstr "逐一的删除这 18 个数据，再新增三个；"

#. Tag: para
#: performance.xml:1394
#, no-c-format
msgid ""
"remove the whole collection in one SQL <literal>DELETE and insert "
"all five current elements one by one"
msgstr "删除整个集合类（只用一句 DELETE 语句），然后逐一添加 5 个数据。"

#. Tag: para
#: performance.xml:1400
#, no-c-format
msgid ""
"Hibernate cannot know that the second option is probably quicker. It would "
"probably be undesirable for Hibernate to be that intuitive as such behavior "
"might confuse database triggers, etc."
msgstr ""
"Hibernate 还没那么聪明，知道第二种选择可能会比较快。（也许让 Hibernate 不这么"
"聪明也是好事，否则可能会引发意外的“数据库触发器”之类的问题。）"

#. Tag: para
#: performance.xml:1404
#, no-c-format
msgid ""
"Fortunately, you can force this behavior (i.e. the second strategy) at any "
"time by discarding (i.e. dereferencing) the original collection and "
"returning a newly instantiated collection with all the current elements."
msgstr ""
"幸运的是，你可以强制使用第二种策略。你需要取消原来的整个集合类（解除其引"
"用），然后再返回一个新的实例化的集合类，只包含需要的元素。有些时候这是非常有"
"用的。 "

#. Tag: para
#: performance.xml:1409
#, no-c-format
msgid ""
"One-shot-delete does not apply to collections mapped <literal>inverse=\"true"
"\"</literal>."
msgstr ""
"显然，一次性删除并不适用于被映射为 <literal>inverse=\"true\" 的集"
"合。 "

#. Tag: title
#: performance.xml:1415
#, no-c-format
msgid "Monitoring performance"
msgstr "监测性能（Monitoring performance）"

#. Tag: para
#: performance.xml:1417
#, no-c-format
msgid ""
"Optimization is not much use without monitoring and access to performance "
"numbers. Hibernate provides a full range of figures about its internal "
"operations. Statistics in Hibernate are available per "
"<literal>SessionFactory."
msgstr ""
"没有监测和性能参数而进行优化是毫无意义的。Hibernate 为其内部操作提供了一系列"
"的示意图，因此可以从 每个 <literal>SessionFactory 抓取其统计数据。"

#. Tag: title
#: performance.xml:1423
#, no-c-format
msgid "Monitoring a SessionFactory"
msgstr "监测 SessionFactory"

#. Tag: para
#: performance.xml:1425
#, no-c-format
msgid ""
"You can access <literal>SessionFactory metrics in two ways. Your "
"first option is to call <literal>sessionFactory.getStatistics() "
"and read or display the <literal>Statistics yourself."
msgstr ""
"你可以有两种方式访问 <literal>SessionFactory 的数据记录，第一种就是"
"自己直接调用 <literal>sessionFactory.getStatistics() 方法读取、显示"
"<literal>统计数据。"

#. Tag: para
#: performance.xml:1430
#, no-c-format
msgid ""
"Hibernate can also use JMX to publish metrics if you enable the "
"<literal>StatisticsService MBean. You can enable a single MBean "
"for all your <literal>SessionFactory or one per factory. See the "
"following code for minimalistic configuration examples:"
msgstr ""
"此外，如果你打开 <literal>StatisticsService MBean 选项，那么 "
"Hibernate 则可以使用 JMX 技术 发布其数据记录。你可以让应用中所有的 "
"<literal>SessionFactory 同时共享一个 MBean，也可以每个 "
"SessionFactory 分配一个 MBean。下面的代码即是其演示代码： "

#. Tag: programlisting
#: performance.xml:1435
#, fuzzy, no-c-format
msgid ""
"// MBean service registration for a specific SessionFactory\n"
"Hashtable tb = new Hashtable();\n"
"tb.put(\"type\", \"statistics\");\n"
"tb.put(\"sessionFactory\", \"myFinancialApp\");\n"
"ObjectName on = new ObjectName(\"hibernate\", tb); // MBean object name\n"
"\n"
"StatisticsService stats = new StatisticsService(); // MBean implementation\n"
"stats.setSessionFactory(sessionFactory); // Bind the stats to a "
"SessionFactory\n"
"server.registerMBean(stats, on); // Register the Mbean on the server"
msgstr ""
"<![CDATA[// MBean service registration for a specific SessionFactory\n"
"Hashtable tb = new Hashtable();\n"
"tb.put(\"type\", \"statistics\");\n"
"tb.put(\"sessionFactory\", \"myFinancialApp\");\n"
"ObjectName on = new ObjectName(\"hibernate\", tb); // MBean object name\n"
"\n"
"StatisticsService stats = new StatisticsService(); // MBean implementation\n"
"stats.setSessionFactory(sessionFactory); // Bind the stats to a "
"SessionFactory\n"
"server.registerMBean(stats, on); // Register the Mbean on the server]]>"

#. Tag: programlisting
#: performance.xml:1437
#, fuzzy, no-c-format
msgid ""
"// MBean service registration for all SessionFactory's\n"
"Hashtable tb = new Hashtable();\n"
"tb.put(\"type\", \"statistics\");\n"
"tb.put(\"sessionFactory\", \"all\");\n"
"ObjectName on = new ObjectName(\"hibernate\", tb); // MBean object name\n"
"\n"
"StatisticsService stats = new StatisticsService(); // MBean implementation\n"
"server.registerMBean(stats, on); // Register the MBean on the server"
msgstr ""
"<![CDATA[// MBean service registration for all SessionFactory's\n"
"Hashtable tb = new Hashtable();\n"
"tb.put(\"type\", \"statistics\");\n"
"tb.put(\"sessionFactory\", \"all\");\n"
"ObjectName on = new ObjectName(\"hibernate\", tb); // MBean object name\n"
"\n"
"StatisticsService stats = new StatisticsService(); // MBean implementation\n"
"server.registerMBean(stats, on); // Register the MBean on the server]]>"

#. Tag: para
#: performance.xml:1439
#, no-c-format
msgid ""
"You can activate and deactivate the monitoring for a "
"<literal>SessionFactory:"
msgstr ""
"你可以通过以下方法打开或关闭 <literal>SessionFactory 的监测功能： "

#. Tag: para
#: performance.xml:1444
#, no-c-format
msgid ""
"at configuration time, set <literal>hibernate.generate_statistics "
"to <literal>false"
msgstr ""
"在配置期间，将 <literal>hibernate.generate_statistics 设置为 "
"<literal>true 或 false；"

#. Tag: para
#: performance.xml:1452
#, no-c-format
msgid ""
"at runtime: <literal>sf.getStatistics().setStatisticsEnabled(true) "
"or <literal>hibernateStatsBean.setStatisticsEnabled(true)"
msgstr ""
"在运行期间，则可以可以通过 <literal>sf.getStatistics().setStatisticsEnabled"
"(true)</literal> 或 hibernateStatsBean.setStatisticsEnabled(true) method."
msgstr ""
"你也可以在程序中调用 <literal>clear() 方法重置统计数据，调用 "
"<literal>logSummary() 在日志中记录（info 级别）其总结。 "

#. Tag: title
#: performance.xml:1464
#, no-c-format
msgid "Metrics"
msgstr "数据记录（Metrics）"

#. Tag: para
#: performance.xml:1466
#, no-c-format
msgid ""
"Hibernate provides a number of metrics, from basic information to more "
"specialized information that is only relevant in certain scenarios. All "
"available counters are described in the <literal>Statistics "
"interface API, in three categories:"
msgstr ""
"Hibernate 提供了一系列数据记录，其记录的内容包括从最基本的信息到与具体场景的"
"特殊信息。所有的测量值都可以由 <literal>Statistics 接口 API 进行访"
"问，主要分为三类："

#. Tag: para
#: performance.xml:1473
#, no-c-format
msgid ""
"Metrics related to the general <literal>Session usage, such as "
"number of open sessions, retrieved JDBC connections, etc."
msgstr ""
"使用 <literal>Session 的普通数据记录，例如打开的 Session 的个数、取"
"得的 JDBC 的连接数等；"

#. Tag: para
#: performance.xml:1479
#, no-c-format
msgid ""
"Metrics related to the entities, collections, queries, and caches as a whole "
"(aka global metrics)."
msgstr "实体、集合、查询、缓存等内容的统一数据记录。"

#. Tag: para
#: performance.xml:1484
#, no-c-format
msgid ""
"Detailed metrics related to a particular entity, collection, query or cache "
"region."
msgstr "和具体实体、集合、查询、缓存相关的详细数据记录"

#. Tag: para
#: performance.xml:1489
#, no-c-format
msgid ""
"For example, you can check the cache hit, miss, and put ratio of entities, "
"collections and queries, and the average time a query needs. Be aware that "
"the number of milliseconds is subject to approximation in Java. Hibernate is "
"tied to the JVM precision and on some platforms this might only be accurate "
"to 10 seconds."
msgstr ""
"例如：你可以检查缓存的命中成功次数，缓存的命中失败次数，实体、集合和查询的使"
"用概率，查询的平均时间等。请注意 Java 中时间的近似精度是毫秒。Hibernate 的数"
"据精度和具体的 JVM 有关，在有些平台上其精度甚至只能精确到 10 秒。 "

#. Tag: para
#: performance.xml:1495
#, no-c-format
msgid ""
"Simple getters are used to access the global metrics (i.e. not tied to a "
"particular entity, collection, cache region, etc.). You can access the "
"metrics of a particular entity, collection or cache region through its name, "
"and through its HQL or SQL representation for queries. Please refer to the "
"<literal>Statistics, EntityStatistics, "
"<literal>CollectionStatistics, "
"<literal>SecondLevelCacheStatistics, and QueryStatistics、EntityStatisticsCollectionStatistics、"
"<literal>SecondLevelCacheStatistics 和 QueryStatistics, "
"<literal>getEntityNames(), getCollectionRoleNames()getSecondLevelCacheRegionNames()."
msgstr ""
"如果你想得到所有实体、集合、查询和缓存区的数据，你可以通过以下方法获得实体、"
"集合、查询和缓存区列表：<literal>getQueries()、"
"<literal>getEntityNames()、getCollectionRoleNames()getSecondLevelCacheRegionNames()。"

#~ msgid "or even:"
#~ msgstr "甚至："

#~ msgid ""
#~ "Now the following code will actually load both the customer <emphasis>and "
#~ "their orders</emphasis>:"
#~ msgstr "下面的代码将实际上加载客户<emphasis>以及订单："

#~ msgid "yes"
#~ msgstr "yes"

#~ msgid ""
#~ "The <literal><cache> element of a class or collection "
#~ "mapping has the following form:"
#~ msgstr ""
#~ "类或者集合映射的“<literal><cache> 元素”可以有下列形式："

#~ msgid ""
#~ "The <literal>usage attribute specifies a cache "
#~ "concurrency strategy</emphasis>."
#~ msgstr ""
#~ "这里的 <literal>usage 属性指明了缓存并发策略（cache "
#~ "concurrency strategy）</emphasis>。"

#~ msgid "read-only"
#~ msgstr "read-only"

#~ msgid "read-write"
#~ msgstr "read-write"

#~ msgid "transactional"
#~ msgstr "transactional"

#~ msgid ""
#~ "This setting creates two new cache regions: one holding cached query "
#~ "result sets (<literal>org.hibernate.cache.StandardQueryCache), "
#~ "the other holding timestamps of the most recent updates to queryable "
#~ "tables (<literal>org.hibernate.cache.UpdateTimestampsCache). "
#~ "Note that the query cache does not cache the state of the actual entities "
#~ "in the result set; it caches only identifier values and results of value "
#~ "type. The query cache should always be used in conjunction with the "
#~ "second-level cache."
#~ msgstr ""
#~ "该设置将会创建两个缓存区域 — 一个用于保存查询结果集（<literal>org."
#~ "hibernate.cache.StandardQueryCache</literal>）； 另一个则用于保存最近查询"
#~ "的一系列表的时间戳（<literal>org.hibernate.cache.UpdateTimestampsCache"
#~ msgstr ""
#~ "<![CDATA["

#~ msgid ""
#~ "<![CDATA["
#~ msgstr ""
#~ "<![CDATA["