Mikhail A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....other classes, including subclasses of C and classes that use C. All a ected classes have to be upgraded as well, so that the new system as a whole remains type correct. A complete upgrade contains class upgrades for all classes that need to change due to some class upgrade already in the upgrade [5, 28, 30, 52]. Completeness is checked using rules analogous to type checking. But some care must be taken when there are objects like iterators, as is discussed in Section 4.4) Our system accepts an upgrade only if it is complete. At this point we say the upgrade is installed. Once an upgrade has been ....

....schema. The schema evolution approach is used in Orion [7] OTGEN [40] O2 [29, 52] GemStone [17, 48] Objectivity DB [47] Versant [50] and PJama [6, 5] systems, and is the only approach available in commercial RDBMS. An extensive survey of the previous schema evolution systems can be found in [30]. None of the previous schema evolution systems provide a way of executing upgrades eciently both in space and time, while allowing programmers to reason locally about the correctness of their upgrades. To be practical, systems must avoid keeping old versions of objects most of the times. Some ....

[Article contains additional citation context not shown here]

M. A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

....other classes, including subclasses of C and classes that use C. All a ected classes have to be upgraded as well, so that the new system as a whole remains type correct. A complete upgrade contains class upgrades for all classes that need to change due to some class upgrade already in the upgrade [53, 21, 4, 25]. Completeness is checked using rules analogous to type checking. Our system accepts an upgrade only if it is complete. At this point we say the upgrade is installed. Once an upgrade has been installed, it is ready to run. An upgrade is executed by running transform functions on all a ected ....

....ObjectStore supports a limited form of eager conversion and no lazy conversion, Versant supports lazy conversion for default transforms but complex transforms require eager conversion, PJama supports eager conversion for user de ned transforms but has no support for lazy conversion. Dmitriev [25] provides an extensive survey of the existing schema evolution systems and analyzes their limitations. The work on O2 explores lazy conversion and complex transforms. This work introduces an upgrade system correctness condition [53] based on the equivalence of lazy and eager conversion, and is ....

M. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

....other classes, including subclasses of C and classes that use C. All a#ected classes have to be upgraded as well, so that the new system as a whole remains type correct. A complete upgrade contains class upgrades for all classes that need to change due to some class upgrade already in the upgrade [53, 21, 4, 25]. Completeness is checked using rules analogous to type checking. Our system accepts an upgrade only if it is complete. At this point we say the upgrade is installed. Once an upgrade has been installed, it is ready to run. An upgrade is executed by running transform functions on all a#ected ....

....ObjectStore supports a limited form of eager conversion and no lazy conversion, Versant supports lazy conversion for default transforms but complex transforms require eager conversion, PJama supports eager conversion for user defined transforms but has no support for lazy conversion. Dmitriev [25] provides an extensive survey of the existing schema evolution systems and analyzes their limitations. The work on O2 explores lazy conversion and complex transforms. This work introduces an upgrade system correctness condition [53] based on the equivalence of lazy and eager conversion, and is ....

M. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

....if a new object didn t t on the page of its old object, we would have to commit two objects instead of one, roughly doubling the commit cost per such object. 5. RELATED WORK The two di erent approaches to modifying the conceptual structure of an object database, broadly categorized, following [14], are schema evolution and schema (or class) versioning. In the evolution approach, the database has one logical schema to which modi cations of class de nitions are applied. Instances are converted (eagerly or lazily, but once and forever) to conform to the latest schema. In the schema or class ....

....relevant to our work; a problem with the versioning approach is the huge amount of storage it requires. The scheme evolution approach is used in the commercial systems O2 [15, 3] GemStone [23, 8] Objectivity DB [22] and Versant [25] and in the research systems Orion [4] OTGen [18] and PJama [2, 14], and is the only approach available in commercial RDBMS. Very few of these systems support general transforms and lazy conversion: Gemstone and Orion do not support user de ned or complex transform functions; ObjectStore supports a limited form of eager conversion and no lazy conversion; Versant ....

[Article contains additional citation context not shown here]

M. Dmitriev. Safe Class and Data Evolution in Large and Long-Lived Java Applications. Technical Report TR-2001.

....if a new object didn t fit on the page of its old object, we would have to commit two objects instead of one, roughly doubling the commit cost per such object. 5. RELATED WORK The two di#erent approaches to modifying the conceptual structure of an object database, broadly categorized, following [14], are schema evolution and schema (or class) versioning. In the evolution approach, the database has one logical schema to which modifications of class definitions are applied. Instances are converted (eagerly or lazily, but once and forever) to conform to the latest schema. In the schema or class ....

....relevant to our work; a problem with the versioning approach is the huge amount of storage it requires. The scheme evolution approach is used in the commercial systems O2 [15, 3] GemStone [23, 8] Objectivity DB [22] and Versant [25] and in the research systems Orion [4] OTGen [18] and PJama [2, 14], and is the only approach available in commercial RDBMS. Very few of these systems support general transforms and lazy conversion: Gemstone and Orion do not support user defined or complex transform functions; ObjectStore supports a limited form of eager conversion and no lazy conversion; Versant ....

[Article contains additional citation context not shown here]

M. Dmitriev. Safe Class and Data Evolution in Large and Long-Lived Java Applications. Technical Report TR-2001.

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Mikhail A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

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M. A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

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M. A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

No context found.

Mikhail A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

No context found.

Mikhail A. Dmitriev. Safe class and data evolution in large and long-lived Java applications. Technical Report TR-2001-98, Sun Microsystems, August 2001.

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