performance.po

hibernate-distribution-3.3.1.GA-dist.zip源码

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:548
#, 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:550
#, no-c-format
msgid ""
"Hibernate3 supports the lazy fetching of individual properties. This "
"optimization technique is also known as <emphasis>fetch groups</emphasis>. "
"Please note that this is mostly a marketing feature, as in practice, "
"optimizing row reads is much more important than optimization of column "
"reads. However, only loading some properties of a class might be useful in "
"extreme cases, when legacy tables have hundreds of columns and the data "
"model can not 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:559
#, no-c-format
msgid ""
"To enable lazy property loading, set the <literal>lazy</literal> 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</literal>，定义该属性为延迟载"
"入。"

#. Tag: programlisting
#: performance.xml:564
#, no-c-format
msgid ""
"<![CDATA[<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 ""

#. Tag: para
#: performance.xml:566
#, no-c-format
msgid ""
"Lazy property loading requires buildtime bytecode instrumentation! If your "
"persistent classes are not enhanced, Hibernate will silently ignore lazy "
"property settings and fall back 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:572
#, 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:576
#, no-c-format
msgid ""
"<![CDATA[<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 ""

#. Tag: para
#: performance.xml:578
#, fuzzy, no-c-format
msgid ""
"A different (better?) way to avoid 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:585
#, no-c-format
msgid ""
"You may 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</literal>，强行抓取所有内容。"

#. Tag: title
#: performance.xml:595
#, no-c-format
msgid "The Second Level Cache"
msgstr "二级缓存（The Second Level Cache）"

#. Tag: para
#: performance.xml:597
#, no-c-format
msgid ""
"A Hibernate <literal>Session</literal> is a transaction-level cache of "
"persistent data. It is possible to configure a cluster or JVM-level "
"(<literal>SessionFactory</literal>-level) cache on a class-by-class and "
"collection-by-collection basis. You may even plug in a clustered cache. Be "
"careful. Caches are never aware of changes made to the persistent store by "
"another application (though they may be configured to regularly expire "
"cached data)."
msgstr ""
"Hibernate的<literal>Session</literal>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</literal>)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:605
#, 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 <literal>hibernate.cache."
"provider_class</literal>. Hibernate comes bundled with a number of built-in "
"integrations with open-source cache providers (listed below); additionally, "
"you could implement your own and plug it in as outlined above. Note that "
"versions prior to 3.2 defaulted to use EhCache as the default cache "
"provider; that is no longer the case as of 3.2."
msgstr ""
"通过在<literal>hibernate.cache.provider_class</literal>属性中指定"
"<literal>org.hibernate.cache.CacheProvider</literal>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:616
#, no-c-format
msgid "Cache Providers"
msgstr "缓存策略提供商（Cache Providers）"

#. Tag: entry
#: performance.xml:625 performance.xml:813
#, no-c-format
msgid "Cache"
msgstr "Cache"

#. Tag: entry
#: performance.xml:626
#, no-c-format
msgid "Provider class"
msgstr "Provider class"

#. Tag: entry
#: performance.xml:627
#, no-c-format
msgid "Type"
msgstr "Type"

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

#. Tag: entry
#: performance.xml:629
#, no-c-format
msgid "Query Cache Supported"
msgstr "Query Cache Supported"

#. Tag: entry
#: performance.xml:634 performance.xml:822
#, no-c-format
msgid "Hashtable (not intended for production use)"
msgstr "Hashtable (not intended for production use)"

#. Tag: literal
#: performance.xml:635
#, no-c-format
msgid "org.hibernate.cache.HashtableCacheProvider"
msgstr "org.hibernate.cache.HashtableCacheProvider"

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

#. Tag: entry
#: performance.xml:638 performance.xml:645 performance.xml:652
#: performance.xml:823 performance.xml:824 performance.xml:825
#: performance.xml:830 performance.xml:831 performance.xml:832
#: performance.xml:837 performance.xml:838 performance.xml:839
#: performance.xml:844 performance.xml:845 performance.xml:851
#: performance.xml:854 performance.xml:858 performance.xml:861
#, no-c-format
msgid "<entry>yes</entry>"
msgstr ""

#. Tag: entry
#: performance.xml:641 performance.xml:829
#, no-c-format
msgid "EHCache"
msgstr "EHCache"

#. Tag: literal
#: performance.xml:642
#, no-c-format
msgid "org.hibernate.cache.EhCacheProvider"
msgstr "org.hibernate.cache.EhCacheProvider"

#. Tag: entry
#: performance.xml:643 performance.xml:650
#, no-c-format
msgid "memory, disk"
msgstr "memory, disk"

#. Tag: entry
#: performance.xml:648 performance.xml:836
#, no-c-format
msgid "OSCache"
msgstr "OSCache"

#. Tag: literal
#: performance.xml:649
#, no-c-format
msgid "org.hibernate.cache.OSCacheProvider"
msgstr "org.hibernate.cache.OSCacheProvider"

#. Tag: entry
#: performance.xml:655 performance.xml:843
#, no-c-format
msgid "SwarmCache"
msgstr "SwarmCache"

#. Tag: literal
#: performance.xml:656
#, no-c-format
msgid "org.hibernate.cache.SwarmCacheProvider"
msgstr "org.hibernate.cache.SwarmCacheProvider"

#. Tag: entry
#: performance.xml:657
#, no-c-format
msgid "clustered (ip multicast)"
msgstr "clustered (ip multicast)"

#. Tag: entry
#: performance.xml:658
#, no-c-format
msgid "yes (clustered invalidation)"
msgstr "yes (clustered invalidation)"

#. Tag: entry
#: performance.xml:662 performance.xml:850
#, fuzzy, no-c-format
msgid "JBoss Cache 1.x"
msgstr "JBoss TreeCache"

#. Tag: literal
#: performance.xml:663
#, no-c-format
msgid "org.hibernate.cache.TreeCacheProvider"
msgstr "org.hibernate.cache.TreeCacheProvider"

#. Tag: entry
#: performance.xml:664 performance.xml:671
#, no-c-format
msgid "clustered (ip multicast), transactional"
msgstr "clustered (ip multicast), transactional"

#. Tag: entry
#: performance.xml:665
#, no-c-format
msgid "yes (replication)"
msgstr "yes (replication)"

#. Tag: entry
#: performance.xml:666 performance.xml:673
#, no-c-format
msgid "yes (clock sync req.)"
msgstr "yes (clock sync req.)"

#. Tag: entry
#: performance.xml:669 performance.xml:857
#, fuzzy, no-c-format
msgid "JBoss Cache 2"
msgstr "JBoss TreeCache"

#. Tag: literal
#: performance.xml:670
#, fuzzy, no-c-format
msgid "org.hibernate.cache.jbc2.JBossCacheRegionFactory"
msgstr "org.hibernate.cache.EhCacheProvider"

#. Tag: entry
#: performance.xml:672
#, fuzzy, no-c-format
msgid "yes (replication or invalidation)"
msgstr "yes (clustered invalidation)"

#. Tag: title
#: performance.xml:680
#, no-c-format
msgid "Cache mappings"
msgstr "缓存映射（Cache mappings）"

#. Tag: para
#: performance.xml:682
#, no-c-format
msgid ""
"The <literal>&lt;cache&gt;</literal> element of a class or collection "