Hibernate version 2.1 rc1(29.11.2003)

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Changes in version 2.1 rc1 (29.11.2003)
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* long identifier and discriminator column names are now safely aliased (Max Andersen)
* cleaned up mapping package to allow applications to manipulate metamodel programmatically
* fixed a recent bug where collection sort order was lost in second-level cache
* formula attribute now supported for joined-subclass mappings
* formula properties may now be used anywhere in queries
* dialect-specific query pagination for SQL Server
* fixed a bug where a long path expression ending in collection access by index missed some tables in SQL FROM clause
* fixed a very ancient performance problem where null one-to-one associations caused n+1 selects
* added Session.saveOrUpdateCopy()
* fixed some bugs in Example queries
* fixed some minor bugs in dialect-specific query pagination
* immutable entity passed to update() is now lock()ed instead
* reworked the semantics of nonstrict-read-write
* JCS cache support now deprecated
* fixed some obscure bugs in collection handling
* migrated to CGLIB2 (thanks to Chris Nockleberg)
* fixed bugs in replicate()
* fixed a bug affecting joined-subclass mappings with dynamic-update=true
* performance improvements to boolean type mappings (Bertrand Renuart)
* integrated JBoss TreeCache clustered cache (thanks to Bela Ban and Ben Wang)
* fixed a bug in new query parameter validation (Steve Ebersole)
* fixed a bug where <any> mappings caused unnecessary ObjectDeletedException at flush time
* fixed a bug where associations with property-ref mappings were not properly cached
* throw PropertyValueException when not-null properties are null at flush time
* added unsaved-value attribute to version property mapping (Emmanuel Bernard)
* tolerate classnames containing $ (Steve Ebersole)

JCS被废了，SQL Server增加了分页，很多的显著的改进，我得花时间研究Hibernate2.1了。

好像JCS在分布式Cache的时候有bug，改用SwarmCache了，不知道SwarmCache的性能如何，如果只是单机Cache，估计用JCS的性能会更高吧