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Many object based systems exist that support some form of distribution. Optimal application performance on distributed object based systems demands accurate class fragmentation and the subsequent allocation of these fragments to distributed sites. Vertical fragmentation must minimize application execution time by splitting a class so that all class(More)
Owing to important applications such as mining web page traversal sequences, many algorithms have been introduced in the area of sequential pattern mining over the last decade, most of which have also been modified to support concise representations like closed, maximal, incremental or hierarchical sequences. This article presents a taxonomy of sequential(More)
Processing costs in distributed environments is most often dominated by the network communications required for interprocess communication. It is well-known from distributed relational database design research that careful placement of data \near" the users or processors where it is used is mandatory or system performance will suuer greatly. Data placement(More)
PLWAP algorithm uses a preorder linked, position coded version of WAP tree and eliminates the need to recursively re-construct intermediate WAP trees during sequential mining as done by WAP tree technique. PLWAP produces significant reduction in response time achieved by the WAP algorithm and provides a position code mechanism for remembering the stored(More)
Optimal application performance on a Distributed Object Based System (DOBS) requires class fragmentation and the development of allocation schemes to place fragments at distributed sites so data transfer is minimized. Fragmentation enhances application performance by reducing the amount of irrelevant data accessed and the amount of data transferred(More)
New transaction insertions and old transaction deletions may lead to previously generated association rules no longer being interesting, and new interesting association rules may also appear. Existing association rules maintenance algorithms are Apriori-like, which mostly need to scan the entire database several times in order to update the previously(More)
Data warehouse views typically store large aggregate tables based on a subset of dimension attributes of the main data warehouse fact table. Aggregate views can be stored as 2 n subviews of a data cube with n attributes. Methods have been proposed for selecting only some of the data cube views to materialize in order to speed up query response time,(More)
Web access pattern tree algorithm mines web log access sequences by first storing the original web access sequence database on a prefix tree (WAP-tree). WAP-tree algorithm then mines frequent sequences from the WAP-tree by recursively reconstructing intermediate WAP-trees, starting with their suffix subsequences. This paper proposes an efficient approach(More)