Abstract: A method for obtaining a balanced digital tree structure. The digital tree structure including a first vertical oriented digital tree structure that is susceptible to unbalanced structure of blocks due to modify transactions. The first digital tree including blocks, each, accommodating a plurality of nodes and links originating from the nodes. The method includes the step of constructing few vertical oriented digital tree structure levels. The tress are arranged such that from blocks of a tree in a given level, it is possible to access horizontally all the blocks of the next level, according to a common key value of the accessed block, whereby a balanced horizontal oriented digital tree structure is obtained.

Abstract: A method for encoding hierarchical data stored in an index, partitioned into blocks, over keys representing the data. For every key K representing a record R in the index, the key of the children records of record R are prefixed with K. The method includes traversing to a first R record represented in the index, traversing from the record R to the next sequential R such that the path in the index from the position representing R to the position representing the next sequential R does not include information relating to the children of R. Next, repeating the latter operation for 0 or more R records, and for any 0 or more particular R records, traversing from the particular R to its children. The index constitutes a balanced structure of blocks.

Abstract: A method for encoding XML tree data that includes the step of encoding the semi-structured data into strings of arbitrary length in a way that maintains non-structural and structural information about the XML data, and enables indexing the encoded XML data in a way facilitates efficient search and browsing.

Abstract: A data processing system including a processor device associated with memory device. The processor is capable of running user application programs to communicate with a database management system that includes database file management system, for accessing data records stored in the memory. The database file management system includes: a probabilistic access indexing file (PAIF) having a plurality of nodes and links. The leave nodes of the PAIF are associated with data records accessible to the user application program. A portion of the data record constitutes a search-key. Selected nodes in the PAIF represent an offset of a search key portion within a search key and link(s) originated from each node among the selected nodes. For each of the selected nodes, except for the leaf node, there exists a subordinated node having an offset larger than the offset of the selected node. A search path in the PAIF commences from a root node and ends at a leaf node which is associated with a given search key.

Abstract: In a database file management system for accessing data records that correspond to items in a directory. The directory items are linked to a trie index that is arranged in blocks and being stored in a storage medium. The trie index enables accessing or updating the directory items data records by key or keys and being susceptible to an unbalanced structure of blocks. There is provided a method for constructing a layered index arranged in blocks, which includes the steps of providing the trie index and constructing a representative index over the representative keys of the trie index. The layered index enables accessing or updating the directory items by key or keys and it constitutes a balanced structure of blocks.

Abstract: In a database file management system for accessing data records and being executed on data processing system. The data records are linked to a trie index that is arranged in blocks and being stored in a storage medium. The trie index enables accessing or updating the data records by key or keys and being susceptible to an unbalanced structure of blocks. There is provided a method for constructing a layered index arranged in blocks, which includes the steps of providing the trie index and constructing a representative index over the representative keys of the trie index. The layered index enables accessing or updating the data records by key or keys and it constitutes a balanced structure of blocks.