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Efficient Instant-Fuzzy Search with Proximity

Ranking

Authors:Inci Centidil, Jamshid Esmaelnezhad, Taewoo

Kim, and Chen Li

IDCE Conference 2014

Presented by: Priagung Khusumanegara

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• System finds answers to a query instantly while user types in keywords character-by-character.

• Fuzzy search improves user search experiences by finding relevant answers with keywords similar to query keywords.

• A main computational challenge in this paradigm is the high speed requirement

• At the same time, we also need good ranking functions that consider the proximity of keywords to compute relevance scores

Abstract

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Problem Statement & Proposed

Solution

• Problem Statement:o Achieving efficient time & space complexities.

• Solution: o Index phrases with proper indexing scheme and o Develop an incremental-computation algorithm for efficiently

segmenting a query into phrases and computing relevant answers.

• Result Metrics: Experimental study on real data sets to show the tradeoffs between time, space, and quality of these solutions.

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General Idea of Instant Search

• Instant search returns the answers immediately based on a partial query a user has typed in

• Many users prefer the experience of seeing the search results instantly and formulating their queries accordingly instead of being left in the dark until they hit the search button

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ArchitecturePhrase Validator: • When a search server

receives a request, it first identifies all the valid phrases in the query that are in the dictionary D, and intersects their inverted lists.

• The Phrase Validator identifies the phrases (called “valid phrases”) in the query that are similar to a term in the dictionary D.

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Architecture (Cont’d)Query Plan Builder: • After identifying the valid

phrases, the Query Plan Builder generates a Query Plan Q, which contains all the possible valid segmentations in a specific order.

• The ranking of Q determines the order in which the segmentations will be executed.

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Architecture (Cont’d)Index Searcher: • After Q is generated, the

segmentations are passed into the Index Searcher one by one until the top-k answers are computed, or all the segmentations in the plan are used.

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Architecture (Cont’d)Cache Module: • The Phrase Validator uses

the Cache module to validate a phrase without traversing the trie from scratch,

• While the Index Searcher benefits from the Cache by being able to retrieve the answers to an earlier query to reduce the computational cost.

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Computing Valid Phrases

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Generating Valid Segmentations

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Incremental Computation of Valid Phrases

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Example Table for Architecture

Explanation

• This data is structured in indexed format. Two types of indices are used to structure this data

1. Trie Indices2. Forward Indices

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Index Structure

• Indiceso TrieoForward

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ExperimentsIn the experiments, they implemented the following method:1. FindAll (“FA”)2. QuerySegmentation (“QS”)3. Term Pair (“TP”)

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Efficiency of Computing Valid Phrases

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Query Time

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Cache Hit Rate

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Scalability

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Conclusion• They studied how to improve ranking of an

instant-fuzzy search system by considering proximity information when we need to compute top-k answers

• They presented an incremental-computation algorithm for finding the indexed phrases in a query efficiently

• The experiments on real data showed the efficiency of the proposed technique for 2-keyword and 3-keyword queries that are common in search applications.