Document (#33043)

Author

Cacheda, F.
Plachouras, V.
Ounis, l.

Title

¬A case study of distributed information retrieval architectures to index one terabyte of text

Source

Information processing and management. 41(2005) no.5, S.1141-1162

Year

2005

Abstract

The increasing number of documents to be indexed in many environments (Web, intranets, digital libraries) and the limitations of a single centralised index (lack of scalability, server overloading and failures), lead to the use of distributed information retrieval systems to efficiently search and locate the desired information. This work is a case study of different architectures for a distributed information retrieval system, in order to provide a guide to approximate the optimal architecture with a specific set of resources. We analyse the effectiveness of a distributed, replicated and clustered architecture simulating a variable number of workstations (from 1 up to 4096). A collection of approximately 94 million documents and 1 terabyte (TB) of text is used to test the performance of the different architectures. In a purely distributed information retrieval system, the brokers become the bottleneck due to the high number of local answer sets to be sorted. In a replicated system, the network is the bottleneck due to the high number of query servers and the continuous data interchange with the brokers. Finally, we demonstrate that a clustered system will outperform a replicated system if a high number of query servers is used, essentially due to the reduction of the network load. However a change in the distribution of the users' queries could reduce the performance of a clustered system.

Similar documents (author)

1. He, B.; Ounis, I.: Combining fields for query expansion and adaptive query expansion (2007) 4.81

   4.811013 = sum of:
     4.811013 = weight(author_txt:ounis in 1926) [ClassicSimilarity], result of:
       4.811013 = fieldWeight in 1926, product of:
         1.0 = tf(freq=1.0), with freq of:
           1.0 = termFreq=1.0
         9.622026 = idf(docFreq=7, maxDocs=44421)
         0.5 = fieldNorm(doc=1926)
   

2. Lioma, C.; Ounis, I.: ¬A syntactically-based query reformulation technique for information retrieval (2008) 4.81

   4.811013 = sum of:
     4.811013 = weight(author_txt:ounis in 3031) [ClassicSimilarity], result of:
       4.811013 = fieldWeight in 3031, product of:
         1.0 = tf(freq=1.0), with freq of:
           1.0 = termFreq=1.0
         9.622026 = idf(docFreq=7, maxDocs=44421)
         0.5 = fieldNorm(doc=3031)
   

3. Chang, Y.; Ounis, I.; Kim, M.: Query reformulation using automatically generated query concepts from a document space (2006) 3.61

   3.60826 = sum of:
     3.60826 = weight(author_txt:ounis in 1972) [ClassicSimilarity], result of:
       3.60826 = fieldWeight in 1972, product of:
         1.0 = tf(freq=1.0), with freq of:
           1.0 = termFreq=1.0
         9.622026 = idf(docFreq=7, maxDocs=44421)
         0.375 = fieldNorm(doc=1972)
   

4. Cacheda, F.; Carneiro, V.; Plachouras, V.; Ounis, I.: Performance analysis of distributed information retrieval architectures using an improved network simulation model (2007) 3.01

   3.0068831 = sum of:
     3.0068831 = weight(author_txt:ounis in 1903) [ClassicSimilarity], result of:
       3.0068831 = fieldWeight in 1903, product of:
         1.0 = tf(freq=1.0), with freq of:
           1.0 = termFreq=1.0
         9.622026 = idf(docFreq=7, maxDocs=44421)
         0.3125 = fieldNorm(doc=1903)
   

5. Gray, A.J.G.; Gray, N.; Hall, C.W.; Ounis, I.: Finding the right term : retrieving and exploring semantic concepts in astronomical vocabularies (2010) 3.01

   3.0068831 = sum of:
     3.0068831 = weight(author_txt:ounis in 235) [ClassicSimilarity], result of:
       3.0068831 = fieldWeight in 235, product of:
         1.0 = tf(freq=1.0), with freq of:
           1.0 = termFreq=1.0
         9.622026 = idf(docFreq=7, maxDocs=44421)
         0.3125 = fieldNorm(doc=235)
   

Similar documents (content)

1. Cacheda, F.; Carneiro, V.; Plachouras, V.; Ounis, I.: Performance analysis of distributed information retrieval architectures using an improved network simulation model (2007) 0.46

   0.4614764 = sum of:
     0.4614764 = product of:
       1.04881 = sum of:
         0.015389666 = weight(abstract_txt:documents in 1903) [ClassicSimilarity], result of:
           0.015389666 = score(doc=1903,freq=1.0), product of:
             0.059717543 = queryWeight, product of:
               1.0204015 = boost
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.014193308 = queryNorm
             0.25770763 = fieldWeight in 1903, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.07508398 = weight(abstract_txt:centralised in 1903) [ClassicSimilarity], result of:
           0.07508398 = score(doc=1903,freq=1.0), product of:
             0.1363444 = queryWeight, product of:
               1.0902442 = boost
               8.811096 = idf(docFreq=17, maxDocs=44421)
               0.014193308 = queryNorm
             0.5506935 = fieldWeight in 1903, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.811096 = idf(docFreq=17, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.048530787 = weight(abstract_txt:network in 1903) [ClassicSimilarity], result of:
           0.048530787 = score(doc=1903,freq=5.0), product of:
             0.07509956 = queryWeight, product of:
               1.1442971 = boost
               4.6239696 = idf(docFreq=1184, maxDocs=44421)
               0.014193308 = queryNorm
             0.6462194 = fieldWeight in 1903, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               4.6239696 = idf(docFreq=1184, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.023522565 = weight(abstract_txt:index in 1903) [ClassicSimilarity], result of:
           0.023522565 = score(doc=1903,freq=1.0), product of:
             0.07923899 = queryWeight, product of:
               1.1754105 = boost
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.014193308 = queryNorm
             0.29685596 = fieldWeight in 1903, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.013453695 = weight(abstract_txt:information in 1903) [ClassicSimilarity], result of:
           0.013453695 = score(doc=1903,freq=3.0), product of:
             0.0513787 = queryWeight, product of:
               1.4965171 = boost
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.014193308 = queryNorm
             0.26185355 = fieldWeight in 1903, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.026089104 = weight(abstract_txt:retrieval in 1903) [ClassicSimilarity], result of:
           0.026089104 = score(doc=1903,freq=2.0), product of:
             0.08490278 = queryWeight, product of:
               1.7206639 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.014193308 = queryNorm
             0.3072821 = fieldWeight in 1903, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.2765681 = weight(abstract_txt:brokers in 1903) [ClassicSimilarity], result of:
           0.2765681 = score(doc=1903,freq=2.0), product of:
             0.3251925 = queryWeight, product of:
               2.3811698 = boost
               9.622026 = idf(docFreq=7, maxDocs=44421)
               0.014193308 = queryNorm
             0.850475 = fieldWeight in 1903, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               9.622026 = idf(docFreq=7, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.056500964 = weight(abstract_txt:system in 1903) [ClassicSimilarity], result of:
           0.056500964 = score(doc=1903,freq=5.0), product of:
             0.119868055 = queryWeight, product of:
               2.5039892 = boost
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.014193308 = queryNorm
             0.47135964 = fieldWeight in 1903, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.038820982 = weight(abstract_txt:number in 1903) [ClassicSimilarity], result of:
           0.038820982 = score(doc=1903,freq=1.0), product of:
             0.1501897 = queryWeight, product of:
               2.5586457 = boost
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.014193308 = queryNorm
             0.25847965 = fieldWeight in 1903, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.23952618 = weight(abstract_txt:replicated in 1903) [ClassicSimilarity], result of:
           0.23952618 = score(doc=1903,freq=1.0), product of:
             0.426136 = queryWeight, product of:
               3.3384113 = boost
               8.993418 = idf(docFreq=14, maxDocs=44421)
               0.014193308 = queryNorm
             0.5620886 = fieldWeight in 1903, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.993418 = idf(docFreq=14, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
         0.23532386 = weight(abstract_txt:distributed in 1903) [ClassicSimilarity], result of:
           0.23532386 = score(doc=1903,freq=5.0), product of:
             0.29200017 = queryWeight, product of:
               3.567645 = boost
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.014193308 = queryNorm
             0.80590314 = fieldWeight in 1903, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.0625 = fieldNorm(doc=1903)
       0.44 = coord(11/25)
   

2. Town, C.; Harrison, K.: Large-scale grid computing for content-based image retrieval (2010) 0.17

   0.17246403 = sum of:
     0.17246403 = product of:
       0.43116006 = sum of:
         0.012674302 = weight(abstract_txt:text in 934) [ClassicSimilarity], result of:
           0.012674302 = score(doc=934,freq=1.0), product of:
             0.05735348 = queryWeight, product of:
               4.040882 = idf(docFreq=2122, maxDocs=44421)
               0.014193308 = queryNorm
             0.22098574 = fieldWeight in 934, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.040882 = idf(docFreq=2122, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.026783573 = weight(abstract_txt:performance in 934) [ClassicSimilarity], result of:
           0.026783573 = score(doc=934,freq=2.0), product of:
             0.074962854 = queryWeight, product of:
               1.1432551 = boost
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.014193308 = queryNorm
             0.35729125 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.020582246 = weight(abstract_txt:index in 934) [ClassicSimilarity], result of:
           0.020582246 = score(doc=934,freq=1.0), product of:
             0.07923899 = queryWeight, product of:
               1.1754105 = boost
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.014193308 = queryNorm
             0.25974897 = fieldWeight in 934, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.021173047 = weight(abstract_txt:case in 934) [ClassicSimilarity], result of:
           0.021173047 = score(doc=934,freq=1.0), product of:
             0.08074816 = queryWeight, product of:
               1.1865511 = boost
               4.794713 = idf(docFreq=998, maxDocs=44421)
               0.014193308 = queryNorm
             0.26221088 = fieldWeight in 934, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.794713 = idf(docFreq=998, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.022827966 = weight(abstract_txt:retrieval in 934) [ClassicSimilarity], result of:
           0.022827966 = score(doc=934,freq=2.0), product of:
             0.08490278 = queryWeight, product of:
               1.7206639 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.014193308 = queryNorm
             0.26887184 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.07109033 = weight(abstract_txt:servers in 934) [ClassicSimilarity], result of:
           0.07109033 = score(doc=934,freq=1.0), product of:
             0.1810579 = queryWeight, product of:
               1.7767603 = boost
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.014193308 = queryNorm
             0.39263868 = fieldWeight in 934, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.04649464 = weight(abstract_txt:high in 934) [ClassicSimilarity], result of:
           0.04649464 = score(doc=934,freq=2.0), product of:
             0.12394608 = queryWeight, product of:
               1.8004544 = boost
               4.8502827 = idf(docFreq=944, maxDocs=44421)
               0.014193308 = queryNorm
             0.3751199 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.8502827 = idf(docFreq=944, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.03126755 = weight(abstract_txt:system in 934) [ClassicSimilarity], result of:
           0.03126755 = score(doc=934,freq=2.0), product of:
             0.119868055 = queryWeight, product of:
               2.5039892 = boost
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.014193308 = queryNorm
             0.26084974 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.04803851 = weight(abstract_txt:number in 934) [ClassicSimilarity], result of:
           0.04803851 = score(doc=934,freq=2.0), product of:
             0.1501897 = queryWeight, product of:
               2.5586457 = boost
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.014193308 = queryNorm
             0.31985223 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
         0.1302279 = weight(abstract_txt:distributed in 934) [ClassicSimilarity], result of:
           0.1302279 = score(doc=934,freq=2.0), product of:
             0.29200017 = queryWeight, product of:
               3.567645 = boost
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.014193308 = queryNorm
             0.44598567 = fieldWeight in 934, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.0546875 = fieldNorm(doc=934)
       0.4 = coord(10/25)
   

3. Meldelzon, A.O.; Mihaila, G.A.; Milo, T.: Querying the World Wide Web (1997) 0.17

   0.16507551 = sum of:
     0.16507551 = product of:
       0.515861 = sum of:
         0.027205342 = weight(abstract_txt:documents in 929) [ClassicSimilarity], result of:
           0.027205342 = score(doc=929,freq=2.0), product of:
             0.059717543 = queryWeight, product of:
               1.0204015 = boost
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.014193308 = queryNorm
             0.455567 = fieldWeight in 929, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.03836696 = weight(abstract_txt:network in 929) [ClassicSimilarity], result of:
           0.03836696 = score(doc=929,freq=2.0), product of:
             0.07509956 = queryWeight, product of:
               1.1442971 = boost
               4.6239696 = idf(docFreq=1184, maxDocs=44421)
               0.014193308 = queryNorm
             0.5108813 = fieldWeight in 929, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.6239696 = idf(docFreq=1184, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.058806412 = weight(abstract_txt:index in 929) [ClassicSimilarity], result of:
           0.058806412 = score(doc=929,freq=4.0), product of:
             0.07923899 = queryWeight, product of:
               1.1754105 = boost
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.014193308 = queryNorm
             0.7421399 = fieldWeight in 929, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               4.7496953 = idf(docFreq=1044, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.041708514 = weight(abstract_txt:query in 929) [ClassicSimilarity], result of:
           0.041708514 = score(doc=929,freq=2.0), product of:
             0.07939911 = queryWeight, product of:
               1.1765975 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.014193308 = queryNorm
             0.52530205 = fieldWeight in 929, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.009709368 = weight(abstract_txt:information in 929) [ClassicSimilarity], result of:
           0.009709368 = score(doc=929,freq=1.0), product of:
             0.0513787 = queryWeight, product of:
               1.4965171 = boost
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.014193308 = queryNorm
             0.18897653 = fieldWeight in 929, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.032611378 = weight(abstract_txt:retrieval in 929) [ClassicSimilarity], result of:
           0.032611378 = score(doc=929,freq=2.0), product of:
             0.08490278 = queryWeight, product of:
               1.7206639 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.014193308 = queryNorm
             0.3841026 = fieldWeight in 929, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.17590296 = weight(abstract_txt:servers in 929) [ClassicSimilarity], result of:
           0.17590296 = score(doc=929,freq=3.0), product of:
             0.1810579 = queryWeight, product of:
               1.7767603 = boost
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.014193308 = queryNorm
             0.9715288 = fieldWeight in 929, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
         0.13155003 = weight(abstract_txt:distributed in 929) [ClassicSimilarity], result of:
           0.13155003 = score(doc=929,freq=1.0), product of:
             0.29200017 = queryWeight, product of:
               3.567645 = boost
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.014193308 = queryNorm
             0.45051354 = fieldWeight in 929, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.078125 = fieldNorm(doc=929)
       0.32 = coord(8/25)
   

4. Cheng, C.-S.; Chung, C.-P.; Shann, J.J.-J.: Fast query evaluation through document identifier assignment for inverted file-based information retrieval systems (2006) 0.16

   0.15691091 = sum of:
     0.15691091 = product of:
       0.4358636 = sum of:
         0.021764275 = weight(abstract_txt:documents in 1979) [ClassicSimilarity], result of:
           0.021764275 = score(doc=1979,freq=2.0), product of:
             0.059717543 = queryWeight, product of:
               1.0204015 = boost
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.014193308 = queryNorm
             0.3644536 = fieldWeight in 1979, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.123322 = idf(docFreq=1954, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.037489194 = weight(abstract_txt:performance in 1979) [ClassicSimilarity], result of:
           0.037489194 = score(doc=1979,freq=3.0), product of:
             0.074962854 = queryWeight, product of:
               1.1432551 = boost
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.014193308 = queryNorm
             0.5001036 = fieldWeight in 1979, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.062423594 = weight(abstract_txt:query in 1979) [ClassicSimilarity], result of:
           0.062423594 = score(doc=1979,freq=7.0), product of:
             0.07939911 = queryWeight, product of:
               1.1765975 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.014193308 = queryNorm
             0.78620017 = fieldWeight in 1979, product of:
               2.6457512 = tf(freq=7.0), with freq of:
                 7.0 = termFreq=7.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.010984897 = weight(abstract_txt:information in 1979) [ClassicSimilarity], result of:
           0.010984897 = score(doc=1979,freq=2.0), product of:
             0.0513787 = queryWeight, product of:
               1.4965171 = boost
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.014193308 = queryNorm
             0.21380253 = fieldWeight in 1979, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.026089104 = weight(abstract_txt:retrieval in 1979) [ClassicSimilarity], result of:
           0.026089104 = score(doc=1979,freq=2.0), product of:
             0.08490278 = queryWeight, product of:
               1.7206639 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.014193308 = queryNorm
             0.3072821 = fieldWeight in 1979, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.037573345 = weight(abstract_txt:high in 1979) [ClassicSimilarity], result of:
           0.037573345 = score(doc=1979,freq=1.0), product of:
             0.12394608 = queryWeight, product of:
               1.8004544 = boost
               4.8502827 = idf(docFreq=944, maxDocs=44421)
               0.014193308 = queryNorm
             0.30314267 = fieldWeight in 1979, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.8502827 = idf(docFreq=944, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.025268 = weight(abstract_txt:system in 1979) [ClassicSimilarity], result of:
           0.025268 = score(doc=1979,freq=1.0), product of:
             0.119868055 = queryWeight, product of:
               2.5039892 = boost
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.014193308 = queryNorm
             0.21079844 = fieldWeight in 1979, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.372775 = idf(docFreq=4140, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.054901157 = weight(abstract_txt:number in 1979) [ClassicSimilarity], result of:
           0.054901157 = score(doc=1979,freq=2.0), product of:
             0.1501897 = queryWeight, product of:
               2.5586457 = boost
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.014193308 = queryNorm
             0.36554542 = fieldWeight in 1979, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.1356745 = idf(docFreq=1930, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
         0.15937003 = weight(abstract_txt:clustered in 1979) [ClassicSimilarity], result of:
           0.15937003 = score(doc=1979,freq=1.0), product of:
             0.32477605 = queryWeight, product of:
               2.9144576 = boost
               7.85132 = idf(docFreq=46, maxDocs=44421)
               0.014193308 = queryNorm
             0.4907075 = fieldWeight in 1979, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.85132 = idf(docFreq=46, maxDocs=44421)
               0.0625 = fieldNorm(doc=1979)
       0.36 = coord(9/25)
   

5. Miller, R.S.: Textual databases : an object-based model (1993) 0.14

   0.13998811 = sum of:
     0.13998811 = product of:
       0.69994056 = sum of:
         0.028969832 = weight(abstract_txt:text in 625) [ClassicSimilarity], result of:
           0.028969832 = score(doc=625,freq=1.0), product of:
             0.05735348 = queryWeight, product of:
               4.040882 = idf(docFreq=2122, maxDocs=44421)
               0.014193308 = queryNorm
             0.50511026 = fieldWeight in 625, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.040882 = idf(docFreq=2122, maxDocs=44421)
               0.125 = fieldNorm(doc=625)
         0.02690739 = weight(abstract_txt:information in 625) [ClassicSimilarity], result of:
           0.02690739 = score(doc=625,freq=3.0), product of:
             0.0513787 = queryWeight, product of:
               1.4965171 = boost
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.014193308 = queryNorm
             0.5237071 = fieldWeight in 625, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               2.4188995 = idf(docFreq=10748, maxDocs=44421)
               0.125 = fieldNorm(doc=625)
         0.1624922 = weight(abstract_txt:servers in 625) [ClassicSimilarity], result of:
           0.1624922 = score(doc=625,freq=1.0), product of:
             0.1810579 = queryWeight, product of:
               1.7767603 = boost
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.014193308 = queryNorm
             0.89745986 = fieldWeight in 625, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.179679 = idf(docFreq=91, maxDocs=44421)
               0.125 = fieldNorm(doc=625)
         0.2710911 = weight(abstract_txt:architectures in 625) [ClassicSimilarity], result of:
           0.2710911 = score(doc=625,freq=1.0), product of:
             0.2915433 = queryWeight, product of:
               2.7613235 = boost
               7.438788 = idf(docFreq=70, maxDocs=44421)
               0.014193308 = queryNorm
             0.9298485 = fieldWeight in 625, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.438788 = idf(docFreq=70, maxDocs=44421)
               0.125 = fieldNorm(doc=625)
         0.21048005 = weight(abstract_txt:distributed in 625) [ClassicSimilarity], result of:
           0.21048005 = score(doc=625,freq=1.0), product of:
             0.29200017 = queryWeight, product of:
               3.567645 = boost
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.014193308 = queryNorm
             0.7208217 = fieldWeight in 625, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7665734 = idf(docFreq=377, maxDocs=44421)
               0.125 = fieldNorm(doc=625)
       0.2 = coord(5/25)