{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T09:00:19Z","timestamp":1775638819155,"version":"3.50.1"},"reference-count":13,"publisher":"Association for Computing Machinery (ACM)","issue":"13","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Proc. VLDB Endow."],"published-print":{"date-parts":[[2014,8]]},"abstract":"<jats:p>Many workloads for analytical processing in commercial RDBMSs are dominated by snowstorm queries, which are characterized by references to multiple large fact tables and their associated smaller dimension tables. This paper describes a technique for bushy join tree optimization for snowstorm queries in Oracle database system. This technique generates bushy join trees containing subtrees that produce substantially reduced sets of rows and, therefore, their joins with other subtrees are generally much more efficient than joins in the left-deep trees.<\/jats:p>\n          <jats:p>The generation of bushy join trees within an existing commercial physical optimizer requires extensive changes to the optimizer. Further, the optimizer will have to consider a large join permutation search space to generate efficient bushy join trees. The novelty of the approach is that bushy join trees can be generated outside the physical optimizer using logical query transformation that explores a considerably pruned search space. The paper describes an algorithm for generating optimal bushy join trees for snowstorm queries using an existing query transformation framework. It also presents performance results for this optimization, which show significant execution time improvements.<\/jats:p>","DOI":"10.14778\/2733004.2733017","type":"journal-article","created":{"date-parts":[[2015,5,12]],"date-time":"2015-05-12T15:37:52Z","timestamp":1431445072000},"page":"1452-1461","source":"Crossref","is-referenced-by-count":13,"title":["Of snowstorms and bushy trees"],"prefix":"10.14778","volume":"7","author":[{"given":"Rafi","family":"Ahmed","sequence":"first","affiliation":[{"name":"Oracle Corporation, Redwood Shores, CA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rajkumar","family":"Sen","sequence":"additional","affiliation":[{"name":"Xplain.Io, San Jose, CA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meikel","family":"Poess","sequence":"additional","affiliation":[{"name":"Oracle Corporation, Redwood Shores, CA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sunil","family":"Chakkappen","sequence":"additional","affiliation":[{"name":"Oracle Corporation, Redwood Shores, CA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2014,8]]},"reference":[{"key":"e_1_2_1_1_1","volume-title":"Proceedings of the 32nd VLDB Conference","author":"Ahmed R.","year":"2006","unstructured":"Ahmed , R. , Lee , A. , Witkowski , A. , Das , D. , Su , H. , Cruanes , T. , and Zait , M . Cost-Based Query Transformation in Oracle . Proceedings of the 32nd VLDB Conference , Seoul, S. Korea , 2006 . Ahmed, R., Lee, A., Witkowski, A., Das, D., Su, H., Cruanes, T., and Zait, M. Cost-Based Query Transformation in Oracle. Proceedings of the 32nd VLDB Conference, Seoul, S. Korea, 2006."},{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.14778\/1687553.1687563"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1145\/223784.223846"},{"key":"e_1_2_1_4_1","volume-title":"Database System Implementation","author":"Garcia-Molina H.","year":"2000","unstructured":"Garcia-Molina , H. , Ullman , J. D. , and Widom , J . Database System Implementation . Prentice Hall , 2000 . Garcia-Molina, H., Ullman, J. D., and Widom, J. Database System Implementation. Prentice Hall, 2000."},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1145\/115790.115813"},{"key":"e_1_2_1_6_1","volume-title":"The Data Warehouse Toolkit: The Complete Guide to Dimensional Modeling","author":"Kimball R.","year":"2002","unstructured":"Kimball , R. and Ross , M . The Data Warehouse Toolkit: The Complete Guide to Dimensional Modeling . John Wiley and Sons, Inc. , 2nd Edition , 2002 . Kimball, R. and Ross, M. The Data Warehouse Toolkit: The Complete Guide to Dimensional Modeling. John Wiley and Sons, Inc., 2nd Edition, 2002."},{"key":"e_1_2_1_7_1","volume-title":"Proceedings of the 32nd VLDB Conference","author":"Moerkotte G.","year":"2006","unstructured":"Moerkotte , G. , and Neumann , T . Analysis of Two Existing and One New Dynamic Programming Algorithm for the Generation of Optimal Bushy Join Trees with Cross Products . Proceedings of the 32nd VLDB Conference , Seoul, S. Korea , 2006 . Moerkotte, G., and Neumann, T. Analysis of Two Existing and One New Dynamic Programming Algorithm for the Generation of Optimal Bushy Join Trees with Cross Products. Proceedings of the 32nd VLDB Conference, Seoul, S. Korea, 2006."},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/211990.212001"},{"key":"e_1_2_1_10_1","volume-title":"Proceedings of the 16th VLDB","author":"Ono K.","year":"1990","unstructured":"Ono , K. , and Lohman , G. M . Measuring the Complexity of Join Enumeration in Query Optimization ., Proceedings of the 16th VLDB , Conference, Brisbane, Australia , 1990 . Ono, K., and Lohman, G. M. Measuring the Complexity of Join Enumeration in Query Optimization., Proceedings of the 16th VLDB, Conference, Brisbane, Australia, 1990."},{"key":"e_1_2_1_11_1","volume-title":"Proceedings of the 32nd VLDB Conference","author":"Othayoth R.","year":"2006","unstructured":"Othayoth , R. , and Poess , M . The Making of TPC-DS . Proceedings of the 32nd VLDB Conference , Seoul, S. Korea , 2006 . Othayoth, R., and Poess, M. The Making of TPC-DS. Proceedings of the 32nd VLDB Conference, Seoul, S. Korea, 2006."},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1145\/582095.582099"},{"key":"e_1_2_1_13_1","volume-title":"Proceedings of 16th VLDB","author":"Schneider D. A.","year":"1990","unstructured":"Schneider , D. A. , and DeWitt , D. J. Tradeoffs in Processing of Complex Join Queries via Hashing in Multiprocessor Database Machines . Proceedings of 16th VLDB , Conference, Brisbane, Australia , 1990 . Schneider, D. A., and DeWitt, D. J. Tradeoffs in Processing of Complex Join Queries via Hashing in Multiprocessor Database Machines. Proceedings of 16th VLDB, Conference, Brisbane, Australia, 1990."},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1145\/233269.233317"}],"container-title":["Proceedings of the VLDB Endowment"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.14778\/2733004.2733017","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,28]],"date-time":"2022-12-28T09:40:45Z","timestamp":1672220445000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.14778\/2733004.2733017"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,8]]},"references-count":13,"journal-issue":{"issue":"13","published-print":{"date-parts":[[2014,8]]}},"alternative-id":["10.14778\/2733004.2733017"],"URL":"https:\/\/doi.org\/10.14778\/2733004.2733017","relation":{},"ISSN":["2150-8097"],"issn-type":[{"value":"2150-8097","type":"print"}],"subject":[],"published":{"date-parts":[[2014,8]]}}}