Adaptive time-to-live strategies for query result caching in web search engines

Alici, Sadiye
Altıngövde, İsmail Sengör
Ozcan, Rifat
Barla Cambazoglu, B.
Ulusoy, Özgür
An important research problem that has recently started to receive attention is the freshness issue in search engine result caches. In the current techniques in literature, the cached search result pages are associated with a fixed time-to-live (TTL) value in order to bound the staleness of search results presented to the users, potentially as part of a more complex cache refresh or invalidation mechanism. In this paper, we propose techniques where the TTL values are set in an adaptive manner, on a per-query basis. Our results show that the proposed techniques reduce the fraction of stale results served by the cache and also decrease the fraction of redundant query evaluations on the search engine backend compared to a strategy using a fixed TTL value for all queries.


Timestamp-based result cache invalidation for web search engines
Alici, Sadiye; Altıngövde, İsmail Sengör; Ozcan, Rifat; Cambazoglu, B. Barla; Ulusoy, Özgür (2011-01-01)
The result cache is a vital component for efficiency of large-scale web search engines, and maintaining the freshness of cached query results is the current research challenge. As a remedy to this problem, our work proposes a new mechanism to identify queries whose cached results are stale. The basic idea behind our mechanism is to maintain and compare generation time of query results with update times of posting lists and documents to decide on staleness of query results. The proposed technique is evaluate...
Second Chance: A Hybrid Approach for Dynamic Result Caching in Search Engines
Altıngövde, İsmail Sengör; Barla Cambazoglu, B.; Ulusoy, Ozgur (2011-01-01)
Result caches are vital for efficiency of search engines. In this work, we propose a novel caching strategy in which a dynamic result cache is split into two layers: an HTML cache and a docID cache. The HTML cache in the first layer stores the result pages computed for queries. The docID cache in the second layer stores ids of documents in search results. Experiments under various scenarios show that, in terms of average query processing time, this hybrid caching approach outperforms the traditional approac...
Explicit Search Result Diversification Using Score and Rank Aggregation Methods
Ozdemiray, Ahmet Murat; Altıngövde, İsmail Sengör (2015-06-01)
Search result diversification is one of the key techniques to cope with the ambiguous and underspecified information needs of web users. In the last few years, strategies that are based on the explicit knowledge of query aspects emerged as highly effective ways of diversifying search results. Our contributions in this article are two-fold. First, we extensively evaluate the performance of a state-of-the-art explicit diversification strategy and pin-point its potential weaknesses. We propose basic yet novel ...
Identifying the effectiveness of a web search engine with Turkish domain dependent impacts and global scale information retrieval improvements
Fidan, Güven; Demirörs, Onur; Yöndem, Meltem Turhan; Department of Information Systems (2012)
This study investigates the effectiveness of a Web search engine with newly added or improved features in Web search engine architecture. These features can be categorized into three groups: The impact of link quality and usage information on page importance calculation; the use of Turkish stemmer for indexing and query substitution; and, the use of thumbnails for Web search engine result visualization. As Web search engines have become the primary means for finding and accessing information on the Internet...
Advanced methods for result and score caching in web search engines
Yafay, Erman.; Altıngövde, İsmail Sengör; Department of Computer Engineering (2019)
Search engines employ caching techniques in main memory to improve system efficiency and scalability. In this thesis, we focus on improving the cache performance for web search engines where our contributions can be separated into two main parts. Firstly, we investigate the impact of the sample size for frequency statistics for most popular cache eviction strategies in the literature, and show that cache performance improves with larger samples, i.e., by storing the frequencies of all (or, most of) the quer...
Citation Formats
S. Alici, İ. S. Altıngövde, R. Ozcan, B. Barla Cambazoglu, and Ö. Ulusoy, “Adaptive time-to-live strategies for query result caching in web search engines,” 2012, Accessed: 00, 2020. [Online]. Available: