H. Garcia, T. Allen, B. Blaustein, R. Chilenskas, and D. Ries. Data-patch: Integrating inconsistent copies of a database after a partition. In Proceedings of the 3rd IEEE Symposium on Reliability in Distributed Software and Database Systems, pages 38-48. IEEE, October 1983.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....slightly relaxes the standard notion of serializability in order to enrich the set of transactions allowed in a partitioned system, and uses semantics of the application to determine when serializability can be relaxed. The third approach, which is the most interesting, is called data patch [32]. Data patch abandons serializability altogether and uses an application speci c de nition of correctness. Quorum Consensus [41] lies somewhere in between optimistic and pessimistic replication. Quorum consensus is a replication method for abstract data types (ADTs) This approach to replicated ....

....workloads with high degrees of write sharing across users. 5.2.4 Bayou Bayou [86] is a replicated, weakly consistent storage system designed for a mobile computing environment that includes portable machines with less than ideal network connectivity. Bayou s approach is similar to data patch [32] which we discussed in Section 5.1.1. To maximize availability, users can read and write any accessible replica. Bayou s design has focussed on supporting application speci c mechanisms to detect and resolve the update con icts that naturally arise in such a system, ensuring that replicas move ....

H. Garcia, T. Allen, B. Blaustein, R. Chilenskas, and D. Ries. Data-patch: Integrating inconsistent copies of a database after a partition. In Proceedings of the 3rd IEEE Symposium on Reliability in Distributed Software and Database Systems, pages 38-48. IEEE, October 1983.

....is an NP complete problem [Dav84, Wri83] so some updates may needlessly revoked for the sake of efficient analysis. Optimistic non serializable approaches have been proposed for computer conferencing [Str81] commercial information retrieval services [ABG87] bulletin board [BJS86] databases [BK85, SKS86, GAB83, All83, Fai81], and file directories [FM82, PPR83, Guy87] Most of these base correctness criteria upon the semantics of the data and the operations performed. 1.5.2.4 Replicated directory management The directory replication problem has received particular attention because of the central role it plays is ....

Hector Garcia-Molina, Tim Allen, Barbara Blaustein, R. Mark Chilenskas, and Daniel R. Ries. "Data-patch: Integrating Inconsistent Copies of a Database after a Partition." In Proceedings of the Third IEEE Symposium on Reliability in Distributed Software and Database Systems, pp. 38--44, October 1983.

.... based on the concept of hoard key [2] Gray et al. presented a two tier replication scheme to allow disconnected applications to request tentative transactions that are later applied to a master copy [14] The conflict resolution mechanism in our system is based on the Data Patch tool described in [12]. Major database vendors have just begun to offer standalone databases for hosting on mobile computers a portion of the backend database [28, 34] However, these systems are not portable across system platforms, and they do not provide a uniform framework for adapting the data as we do. As far as ....

H. Garcia-Molina, T. Allan, B. Blaustein, R. M. Chilenskas, and D. R. Ries. Data-Patch: Integrating Inconsistent Copies of a Database after Partition. In Proceedings of the 3rd Symposium on Reliability in Distributed Software and Database Systems, pages 38--44. IEEE, October 1983.

....in many environments [3, 2] Bank automatic tellers and airline reservation systems are are the best known examples of commercial systems where performance and availability take precedence over conservative consistency. Several approaches have been suggested to detect and merge divergent databases [1, 5] in these systems. File replication is another example where the benefits of optimistic replication can often outweigh the costs. There is substantial existing work analyzing the cost of conflicting updates in optimistic filing from several perspectives. Analysis of file system usage [4, 9] ....

Hector Garcia-Molina, Tim Allen, Barbara Blaustein, R. Mark Chilenskas, and Daniel R. Ries. Data-patch: Integrating inconsistent copies of a database after a partition. In Proceedings of the Third IEEE Symposium on Reliability in Distributed Software and Database Systems, pages 38--44, October 1983.

....needed. Many replica control algorithms have been proposed, favoring either low access costs or high data availability. In [4] these algorithms are classified as optimistic or pessimistic replication strategies. Assuming that computer or link failures are unlikely to occur, optimistic strategies [5, 6, 7] allow concurrent read and write access operations. As a consequence, replicas can become mutually inconsistent and must be repaired later; either by a special merge procedure or by rolling back the conflicting access operations. In the worst case, the latter possibility can result in ....

H. Garcia-Molina, T. Allen, B. Blaustein, et al. Data--Patch: Integrating Inconsistent Copies of a Database after a Partition. In Proc. of the 3rd Symposium on Reliability in Distributed Software and Database Systems, pages 38--44. IEEE, 1983.

....will allow a reader to switch from a newer version to an older data version. 1.2 Eventual Data Consistency The purpose of providing consistency guarantees is to maintain the semantics of data. Data accesses do not have to be serialized for maintaining the semantics of several types of data [FM82, All83, GAB83]. For other data types, some minimal inconsistency, or external intervention to restore the semantics of the data is often considered more acceptable than entirely inhibiting data accesses when communication is not possible [Sat89, GHM90, TTP95] Consider a calendar that is shared by several ....

....problem. Later, Heddaya, et al. HHW89] propose a lower overhead solution, although garbage collection is more conservative. The acknowledgment algorithm presented in Section 6.5 borrows several ideas from Wuu. Consistency algorithms that use data semantics provide high data availability. Garcia [GAB83], Sarin [Sar86] and Ladin [LLS90] generalize the directory solution for other data types. Garcia uses a data patch tool that automates the data integration step. The correct final state of a database and corrective measures to reach it are predefined for various potential non serializable ....

Hector Garcia-Molina, Tim Allen, Barbara Blaustein, R. Mark Chilenskas, and Daniel R. Ries. "Data-patch: Integrating Inconsistent Copies of a Database after a Partition." In Proceedings of the Third IEEE Symposium on Reliability in Distributed Software and Database Systems, pp. 38--44, October 1983.

....5 and 6, implementational aspects are given, the evaluation environment will be described, and conclusions for future work are given. 2 Reintegration After Optimistic Decoupled Work 2. 1 Requirements for Reintegration Any of the existing mechanisms such as those in database or file systems (see [10], 15] 16] and [17] support optimistic autonomous collaboration. Decoupled work phases supported by these systems are expected to be short and inconsistencies are simple and occur rarely [4] In contrast, CSCW systems should support intentionally long decoupled work phases. Inconsistencies are ....

....and discussed briefly. Also, systems supporting decoupled work with partly optimistic and partly pessimistic strategies have been developed (see [8] but are not considered in detail in this paper. Existing approaches can be subdivided into reintegration tools for database systems (Data Patch [10], Optimistic Protocol [9] and Log Transformation [11] operating and file systems (Version Vectors [12] Fcomp [13] Unix Diff [14] Application Specific Resolver [15] Conflict Resolvers [16] Disconnected Operation for AFS [17] and Coda [18] File Merge [19] and collaborative systems. ....

Garcia-Molina, H., Allen, T., Blaustein, B., Chilenskas, R. M., Reis, D. R.: DataPatch: Integrating Inconsistent Copies of a Database after a Partition. Proceedings of the 3rd IEEE Symposium on Reliability in Distributed Software and Database Systems, October 1983, N.Y., pp. 38-48.

....off among C, A and P. Bayou provides a set of operating points that trades increasing A and P for 49 decreasing C, allowing application specific (and even update specific) conflict resolution handlers to be invoked in weak consistency scenarios. This is a generalization of the DataPatch method [63] for integrating inconsistent replicas according to application specific correctness criteria, independent of the specific ACID properties. Davidson et al. 39] discuss in detail some examples of optimistic strategies (sacrificing some consistency to preserve availability) and pessimistic ....

H. Garcia, T. Allen, B. Blaustein, R.M. Chilenskas, and D.R. Ries. Data-patch: Integrating inconsistent copies of a database after a partition. In Third IEEE Symposium on Reliability in Distributed Software and Database Systems, pages 38--48, New York, NY, Oct 1983.

....to a version back into the base relation. An example of this command is merge YOURPEOPLE into PERSON that will merge the changes made to YOURPEOPLE back into PERSON. The merge command uses a semi automatic procedure to resolve updates to the underlying relation and the version that conflict [Gae84]. This section described most of the data definition and data manipulation commands in POSTQUEL. The commands that were not described are the commands for defining rules, utility commands that only affect the performance of the system (e.g. define index and modify) and other miscellaneous ....

H. Garcia-Molina and et.al., "DataPatch: Integrating Inconsistent Copies of a Database after a Partition", Tech. Rep. Tech. Rep.# 304, Dept. Elec. Eng. and Comp. Sci., Princeton, NJ, 1984.

....A Merge command is provided that will merge the changes made in a version back into the underlying relation. An example of a Merge command is merge EMPTEST into EMP The Merge command will use a semi automatic procedure to resolve updates to the underlying relation and the version that conflict [GARC84]. This section described POSTGRES support for time varying data. The strategy for implementing these features is described below in the section on system architecture. 3.4. Iteration Queries, Alerters, Triggers, and Rules This section describes the POSTQUEL commands for specifying iterative ....

....insert record into older version 2) if it is a delete, then delete the record in the older version 3) if it is a replace, then do an insert and a delete There is a conflict if one attempts to delete an already deleted record. Such cases must be handled external to the algorithm. The tactics in [GARC84] may be helpful in reconciling these conflicts. An older version can be rolled forward into a newer version by performing the above operations and then renaming the older version. 6. SUMMARY POSTGRES proposes to support complex objects by supporting an extendible type system for defining new ....

Garcia-Molina, H., et. al., "Data-Patch: Integrating Inconsistent copies of a Database after a Partition," Tech. Rep. TR# 304, Dept. Elec. Eng. and Comp. Sci., Princeton Univ., 1984.

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Garcia-Molina, H., Allen, T., Blaustein, B., Chilenskas, R., and Ries, D. DataPatch: Integrating Inconsistent Copies of a Database after a Partition. In Proceedings of the Third Symposium on Reliability in Distributed Software and Database Systems (October 1983).

No context found.

H. Garcia-Molina, T. Allen, B. Blaustein, et al. Data--Patch: Integrating Inconsistent Copies of a Database after a Partition. In Proc. of the 3rd Symp. on Reliability in Distributed Software and Database Systems, pages 38--44. IEEE, 1983.

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