Version Merging Research Articles

Keyword Search in Decentralized Storage Systems

The emerging decentralized storage systems (DSSs), such as InterPlanetary File System (IPFS), Storj, and Sia, provide people with a new storage model. Instead of being centrally managed, the data are sliced up and distributed across the nodes of the network. Furthermore, each data object is uniquely identified by a cryptographic hash (ObjectId) and can only be retrieved by ObjectId. Compared with the search functions provided by the existing centralized storage systems, the application scenarios of the DSSs are subject to certain restrictions. In this paper, we first apply decentralized B+Tree and HashMap to the DSSs to provide keyword search. Both indexes are kept in blocks. Since these blocks may be scattered on multiple nodes, we ensure that all operations involve as few blocks as possible to reduce network cost and response time. In addition, the version control and version merging algorithms are designed to effectively organize the indexes and facilitate data integration. The experimental results prove that our indexes have excellent availability and scalability.

Database versioning and its implementation in geoscience information systems

Many different versions of geoscience data concurrently exist in a database for different geological paradigms, source data, and authors. The aim of this study is to manage these versions in a database management system. Our data include geological surfaces, which are triangulated meshes in this study. Unlike revision/version/source control systems, our data are stored in a central database without local copies. The main contributions of this study include (1) a data model with input/output/manage functions, (2) a mesh comparison function, (3) a version merging strategy, and (4) the implementation of all of the concepts in PostgreSQL and gOcad. The software has been tested using synthetic surfaces and a simple tectonic model of a deformed stratigraphic horizon.

A method of version merging for computer-aided design files based on feature extraction

In order to manage the version files and maintain the latest version of the computer-aided design (CAD) files in asynchronous collaborative systems, one method of version merging for CAD files is proposed to resolve the problem based on feature extraction. First of all, the feature information is extracted based on the feature attribute of CAD files and stored in a XML feature file. Then, analyse the feature file, and the feature difference set is obtained by the given algorithm. Finally, the merging result of the difference set and the master files with application programming interface (API) interface functions is achieved, and then the version merging of CAD files is also realized. The application in Catia validated that the proposed method is feasible and valuable in engineering.

A schema version model for complex objects in object-oriented databases

In this paper, we propose a schema version model which allows to restructure complex object hierarchy in object-oriented databases. This model extends a schema version model, called RiBS , which is based on the concept of Rich Base Schema . In the RiBS model, each schema version is in the form of updatable class hierarchy view over one base schema, called the RiBS layer, which has richer schema information than any existing schema version in the database. In this paper, we introduce new operations for restructuring composite object hierarchy in schema versions, and explain their semantics. We also touch upon the ways to transform queries posed against a restructured composite object hierarchy into one against the base schema. In addition, we identify several types of conflicts during schema version merging which result from the restructuring operations, and provide a semi-automatic algorithm to resolve the conflicts. The originality of this paper lies in that (1) we introduce several new operations to restructure composite object hierarchy, and (2) this extended RiBS model operations raise the concept of data independence in OODBs upto the schema level.

Versions and workspaces in Microsoft repository

This paper describes the version and workspace features of Microsoft Repository, a layer that implements fine-grained objects and relationships on top of Microsoft SQL Server. It supports branching and merging of versions, delta storage, checkout-checkin, and single-version views for version-unaware applications.