Efficient and effective keyword search in XML database

... mandatory and single valued, unless the circle contains a “?” indicating it is optional and single valued, “+” indicating it is mandatory and multi-valued, and “*” indicating it is optional and ... graph in memory which is infeasible for large databases Blinks [25] address these problems by using a bi-level index for pruning and accelerating the search Its main idea is to main...

Ngày tải lên: 05/10/2015, 19:01

... This thesis examines general form keyword search queries in XML data The keyword search for XML documents are important as XML has become the standard for representing web data Existing approaches ... is the original motivation of our work that we intend to develop an efficient approach of processing AND- OR keyword search queries in general form, i.e an...

Ngày tải lên: 05/10/2015, 19:02

... long time to execute when N is large Thus it is only suitable for small databases and is definitely impractical and infeasible for large databases Therefore, for large databases, approximate detection ... size of the database increases, the time in data cleansing grows linearly For very large databases, the data cleansing may take a very long time As the example s...

Ngày tải lên: 17/09/2015, 17:19

... transmitted in any form or by any means—electronic, mechanical, photocopy, recording, or any other except for brief quotations in printed reviews, without the prior permission of the publisher Keyword Search ... Series ISSN Synthesis Lectures on Data Management ISSN pending Keyword Search in Databases Jeffrey Xu Yu, Lu Qin, and Lijun Chang Chinese University of Hong Kong SYNTHES...

Ngày tải lên: 05/07/2014, 23:22

... Steiner Tree-Based Keyword Search 53 3.3.1 Backward Search 53 3.3.2 Dynamic Programming 55 3.3.3 Enumerating Q-subtrees with Polynomial Delay 3.4 Distinct ... Root-Based Keyword Search 69 3.4.1 Bidirectional Search 3.4.2 Bi-Level Indexing 69 71 3.4.3 External Memory Data Graph 3.5 57 73 Subgraph-Based Keyword Search ... 21 2.3.1 Getting All MTJNT s in a Relational Databas...

Ngày tải lên: 05/07/2014, 23:22

... weights), or both In Chapter 2, we focus on supporting keyword search in an rdbms using sql Since this implies making use of the database schema information to issue sql queries in order to find ... etc In Chapter 5, we highlight several interesting research issues regarding keyword search on databases The topics include how to select a database among many possible databases to...

Ngày tải lên: 05/07/2014, 23:22

... Total: each keyword in the query must be contained in at least one tuple of the joining network • Minimal: a joining network of tuples is not total if any tuple is removed Because it is meaningless ... is included in the result of such a selection select * from R where contain(A1 , k1 ) or contain(A2 , k1 ) An l -keyword query returns a set of answers, where an answer is a minimal to...

Ngày tải lên: 05/07/2014, 23:22

... calling CNGen Duplicates that are generated from the same root following different insertion order for the remaining nodes are eliminated by the second condition in the legal node testing (line ... is shown in Algorithm and will be discussed later After processing Ri , the whole space can be divided into two subspaces as discussed in Property-5 by simply removing Ri from GX (line 4), an...

Ngày tải lên: 05/07/2014, 23:22

... joins in order to avoid intermediate join results becoming very SCHEMA-BASED KEYWORD SEARCH ON RELATIONAL DATABASES Join SemiJoin-Join 1M 100K 10K 10M # Temp Tuples 10M # Temp Tuples 26 Join ... evaluated using joins in DISCOVER or S-KWS A join plan is shown in Figure 2.9(b) to process the CN in Figure 2.9(a) using projects and joins The resulting relation, the output of the join...

Ngày tải lên: 05/07/2014, 23:22

... Global-Pipelined algorithm, i.e., it can make Q and topk global to maintain the set of combinations in multiple CN s 2.4 OTHER KEYWORD SEARCH SEMANTICS Processed Area M2 Single−Pipelined M1 33 M2 Skyline−Sweeping ... processed combinations for the Skyline-Sweeping algorithm is shown in Figure 2.15 When there are multiple CN s, it can change the Skyline-Sweeping algorithm using the si...

Ngày tải lên: 05/07/2014, 23:22

... Vk is a set of keyword- tuples where a keyword- tuple vk ∈ Vk contains at least a keyword, and all l keywords in the given l -keyword query must appear in at least one keyword- tuple in Vk ; Vc is ... can be possibly included in a result, and Tmax specifies the maximum number of nodes to be included in a result Distinct Core/Root in rdbms: We outline the approach to process l...

Ngày tải lên: 05/07/2014, 23:22

... virtual keyword- node ki means that tuple t can reach at least a tuple containing ki within Dmax Let Gi be the set of tuples in RDB that can reach at least a tuple containing keyword ki within Dmax, ... DC-Naive() to compute distinct cores is outlined in Algorithm 12 DRNaive() that computes distinct roots can be implemented in the same way as DC-Naive() by replacing line in Algorit...

Ngày tải lên: 05/07/2014, 23:22

... D Although in Figure 3.1(e), there is only one incoming edge for each keyword node, multiple incoming edges into keyword nodes are allowed in general Note that, there is only one keyword node ... stored in an RDB can be captured by a weighted directed graph, GD = (V , E) Each tuple tv in RDB is modeled as a node v ∈ V in GD , associated with keywords contained in the corresp...

Ngày tải lên: 05/07/2014, 23:22

... entry, v, from Fn (line 7) It updates the distance of all the incoming neighbors of v whose shortest distance have not been determined (line 8-11) Then, it inserts v into SPTree (line 12) and returns ... delay 3.3.1 BACKWARD SEARCH Bhalotia et al [2002] enumerate Q-subtrees using a backward search algorithm searching backwards from the nodes that contain keywords Given a set of l keywords...

Ngày tải lên: 05/07/2014, 23:22

... [Ding et al., 2007] DPBF can be modified slightly to output k steiner trees in increasing weight order, denoted as DPBF-K, by terminating DPBF after finding k steiner trees that contain all the keywords ... weight tree is maintained at the top of the queue QT DPBF first initializes QT to be empty (line 1), and inserts T (ki , {ki }) with weight into QT (lines 2-3), for each keyword node in...

Ngày tải lên: 05/07/2014, 23:22