Abstract: The present invention relates to the technical field of data or file synchronization. In particular, the present invention relates to a method and system for data synchronization using character string matching. Provided are a method, computer program product, and system for data synchronization between a source node and target node. An old copy and a new copy of data to be synchronized is received. A block map is generated according to the difference determined using character string matching between the old copy and the new copy. The block map, which includes the position information of unchanged blocks and the position information and contents of changed blocks, is transmitted to a target node.

Abstract: Aspects of the present invention provide a tool for hash-based indexing. In an embodiment, a ranked dataset having a plurality of data items is obtained. Every data item in the ranked dataset has a ranking with respect to every other data item in the ranked dataset. A ranking triplet matrix is created based on the ranked dataset. The ranking triplet matrix has a set of ranking triplets, each of which indicates the relative ranking for a pair of the data items in the ranked dataset. This ranking triplet can be merged with a hash table obtained using a standard hash function and the data items can be indexed based on the results.

Abstract: Aspects of the present invention provide a tool for hash-based indexing. In an embodiment, a ranked dataset having a plurality of data items is obtained. Every data item in the ranked dataset has a ranking with respect to every other data item in the ranked dataset. A ranking triplet matrix is created based on the ranked dataset. The ranking triplet matrix has a set of ranking triplets, each of which indicates the relative ranking for a pair of the data items in the ranked dataset. This ranking triplet can be merged with a hash table obtained using a standard hash function and the data items can be indexed based on the results.

Abstract: A computer system affords a user the ability to interactively formulate, visualize, and modify query plans that are to be posed to a database. The computer system provides query visualization in the form of decision trees having nodes selectable/deselectable to search for alternative query plans with lower or minimum execution time. The estimated cost and/or the execution time of a subtree of a query plan may be mapped according to a rectangle area metaphore, with the area of a rectangle enclosed by a larger rectangle representing a parent node in the plan tree. Query plans may be saved by the system in order to facilitate their visualization, optimization, and/or modification at a later date.