Hibernate example source code file (portability.po)

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The Hibernate portability.po source code

# Language ko-KR translations for PACKAGE package.
# Automatically generated, 2009.
#
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"Report-Msgid-Bugs-To: http://bugs.kde.org\n"
"POT-Creation-Date: 2010-02-04T04:51:22\n"
"PO-Revision-Date: 2009-07-14 19:56+0000\n"
"Last-Translator: Automatically generated\n"
"Language-Team: none\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. Tag: title
#, no-c-format
msgid "Database Portability Considerations"
msgstr ""

#. Tag: title
#, no-c-format
msgid "Portability Basics"
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"One of the selling points of Hibernate (and really Object/Relational Mapping "
"as a whole) is the notion of database portability. This could mean an "
"internal IT user migrating from one database vendor to another, or it could "
"mean a framework or deployable application consuming Hibernate to "
"simultaneously target multiple database products by their users. Regardless "
"of the exact scenario, the basic idea is that you want Hibernate to help you "
"run against any number of databases without changes to your code, and "
"ideally without any changes to the mapping metadata."
msgstr ""

#. Tag: title
#, no-c-format
msgid "Dialect"
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"The first line of portability for Hibernate is the dialect, which is a "
"specialization of the <classname>org.hibernate.dialect.Dialect "
"contract. A dialect encapsulates all the differences in how Hibernate must "
"communicate with a particular database to accomplish some task like getting "
"a sequence value or structuring a SELECT query. Hibernate bundles a wide "
"range of dialects for many of the most popular databases. If you find that "
"your particular database is not among them, it is not terribly difficult to "
"write your own."
msgstr ""

#. Tag: title
#, no-c-format
msgid "Dialect resolution"
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Originally, Hibernate would always require that users specify which dialect "
"to use. In the case of users looking to simultaneously target multiple "
"databases with their build that was problematic. Generally this required "
"their users to configure the Hibernate dialect or defining their own method "
"of setting that value."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Starting with version 3.2, Hibernate introduced the notion of automatically "
"detecting the dialect to use based on the <interfacename>java.sql."
"DatabaseMetaData</interfacename> obtained from a java.sql."
"Connection</interfacename> to that database. This was much better, expect "
"that this resolution was limited to databases Hibernate know about ahead of "
"time and was in no way configurable or overrideable."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Starting with version 3.3, Hibernate has a fare more powerful way to "
"automatically determine which dialect to should be used by relying on a "
"series of delegates which implement the <interfacename>org.hibernate.dialect."
"resolver.DialectResolver</interfacename> which defines only a single method:"
"<programlisting role=\"JAVA\">public Dialect resolveDialect(DatabaseMetaData "
"metaData) throws JDBCConnectionException</programlisting>. The basic "
"contract here is that if the resolver 'understands' the given database "
"metadata then it returns the corresponding Dialect; if not it returns null "
"and the process continues to the next resolver. The signature also "
"identifies <exceptionname>org.hibernate.exception.JDBCConnectionException constant on org.hibernate."
"cfg.Environment</classname>)."
msgstr ""

#. Tag: title
#, no-c-format
msgid "Identifier generation"
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"When considering portability between databases, another important decision "
"is selecting the identifier generation stratagy you want to use. Originally "
"Hibernate provided the <emphasis>native generator for this "
"purpose, which was intended to select between a <emphasis>sequenceidentity, or table "
"strategy depending on the capability of the underlying database. However, an "
"insidious implication of this approach comes about when targtetting some "
"databases which support <emphasis>identity generation and some "
"which do not. <emphasis>identity generation relies on the SQL "
"definition of an IDENTITY (or auto-increment) column to manage the "
"identifier value; it is what is known as a post-insert generation strategy "
"becauase the insert must actually happen before we can know the identifier "
"value. Because Hibernate relies on this identifier value to uniquely "
"reference entities within a persistence context it must then issue the "
"insert immediately when the users requests the entitiy be associated with "
"the session (like via save() e.g.) regardless of current transactional "
"semantics."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Hibernate was changed slightly once the implication of this was better "
"understood so that the insert is delayed in cases where that is feasible."
msgstr ""

#. Tag: note
#, no-c-format
msgid ""
"The underlying issue is that the actual semanctics of the application itself "
"changes in these cases."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Starting with version 3.2.3, Hibernate comes with a set of <ulink url="
"\"http://in.relation.to/2082.lace\">enhanced</ulink> identifier generators "
"targetting portability in a much different way."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"There are specifically 2 bundled <emphasis>enhancedgenerators:"
msgstr ""

#. Tag: para
#, no-c-format
msgid "<classname>org.hibernate.id.enhanced.SequenceStyleGenerator"
msgstr ""

#. Tag: para
#, no-c-format
msgid "<classname>org.hibernate.id.enhanced.TableGenerator"
msgstr ""

#. Tag: note
#, no-c-format
msgid ""
"The idea behind these generators is to port the actual semantics of the "
"identifer value generation to the different databases. For example, the "
"<classname>org.hibernate.id.enhanced.SequenceStyleGenerator "
"mimics the behavior of a sequence on databases which do not support "
"sequences by using a table."
msgstr ""

#. Tag: title
#, no-c-format
msgid "Database functions"
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"This is an area in Hibernate in need of improvement. In terms of portability "
"concerns, this function handling currently works pretty well from HQL; "
"however, it is quite lacking in all other aspects."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"SQL functions can be referenced in many ways by users. However, not all "
"databases support the same set of functions. Hibernate, provides a means of "
"mapping a <emphasis>logical function name to a a delegate which "
"knows how to render that particular function, perhaps even using a totally "
"different physical function call."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"Technically this function registration is handled through the <classname>org."
"hibernate.dialect.function.SQLFunctionRegistry</classname> class which is "
"intended to allow users to provide custom function definitions without "
"having to provide a custom dialect. This specific behavior is not fully "
"completed as of yet."
msgstr ""

#. Tag: para
#, no-c-format
msgid ""
"It is sort of implemented such that users can programatically register "
"functions with the <classname>org.hibernate.cfg.Configuration "
"and those functions will be recognized for HQL."
msgstr ""

#. Tag: title
#, no-c-format
msgid "Type mappings"
msgstr ""

#. Tag: para
#, no-c-format
msgid "This section scheduled for completion at a later date..."
msgstr ""