{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,2]],"date-time":"2025-11-02T16:39:30Z","timestamp":1762101570977},"reference-count":15,"publisher":"Association for Computing Machinery (ACM)","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Proc. VLDB Endow."],"published-print":{"date-parts":[[2009,8]]},"abstract":"<jats:p>A schema mapping is a declarative specification of the relationship between instances of a source schema and a target schema. The data exchange (or data translation) problem asks: given an instance over the source schema, materialize an instance (or solution) over the target schema that satisfies the schema mapping. In general, a given source instance may have numerous different solutions. Among all the solutions, universal solutions and core universal solutions have been singled out and extensively studied. A universal solution is a most general one and also represents the entire space of solutions, while a core universal solution is the smallest universal solution and is unique up to isomorphism (hence, we can talk about the core).<\/jats:p>\n          <jats:p>The problem of designing efficient algorithms for computing the core has attracted considerable attention in recent years. In this paper, we present a method for directly computing the core by SQL queries, when schema mappings are specified by source-to-target tuple-generating dependencies (s-t tgds). Unlike prior methods that, given a source instance, first compute a target instance and then recursively minimize that instance to the core, our method avoids the construction of such intermediate instances. This is done by rewriting the schema mapping into a laconic schema mapping that is specified by first-order s-t tgds with a linear order in the active domain of the source instances. A laconic schema mapping has the property that a \"direct translation\" of the source instance according to the laconic schema mapping produces the core. Furthermore, a laconic schema mapping can be easily translated into SQL, hence it can be optimized and executed by a database system to produce the core. We also show that our results are optimal: the use of the linear order is inevitable and, in general, schema mappings with constraints over the target schema cannot be rewritten to a laconic schema mapping.<\/jats:p>","DOI":"10.14778\/1687627.1687741","type":"journal-article","created":{"date-parts":[[2014,6,24]],"date-time":"2014-06-24T12:17:57Z","timestamp":1403612277000},"page":"1006-1017","source":"Crossref","is-referenced-by-count":20,"title":["Laconic schema mappings"],"prefix":"10.14778","volume":"2","author":[{"given":"Balder","family":"ten Cate","sequence":"first","affiliation":[{"name":"INRIA and ENS Cachan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Laura","family":"Chiticariu","sequence":"additional","affiliation":[{"name":"IBM Almaden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phokion","family":"Kolaitis","sequence":"additional","affiliation":[{"name":"UC Santa Cruz and IBM Almaden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wang-Chiew","family":"Tan","sequence":"additional","affiliation":[{"name":"UC Santa Cruz"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2009,8]]},"reference":[{"key":"e_1_2_1_1_1","first-page":"1267","volume-title":"VLDB (demo)","author":"Bonifati A.","year":"2006","unstructured":"A. Bonifati , E. Q. Chang , T. Ho , L. V. Lakshmanan , and R. Pottinger . HePToX: Marrying XML and Heterogeneity in Your P2P Databases . In VLDB (demo) , pages 1267 -- 1270 , 2006 . A. Bonifati, E. Q. Chang, T. Ho, L. V. Lakshmanan, and R. Pottinger. HePToX: Marrying XML and Heterogeneity in Your P2P Databases. In VLDB (demo), pages 1267--1270, 2006."},{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1145\/800105.803397"},{"key":"e_1_2_1_3_1","volume-title":"UCSC","author":"Chiticariu L.","year":"2005","unstructured":"L. Chiticariu . Computing the Core in Data Exchange: Algorithmic Issues. MS project report. CS Dept ., UCSC , 2005 . L. Chiticariu. Computing the Core in Data Exchange: Algorithmic Issues. MS project report. CS Dept., UCSC, 2005."},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1006\/jcss.1997.1450"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1O16\/j.tcs.2004.10.033"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1145\/1376916.1376922"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1145\/1061318.1061323"},{"key":"e_1_2_1_8_1","first-page":"67","volume-title":"VLDB","author":"Fuxman A.","year":"2006","unstructured":"A. Fuxman , M. A. Hern\u00e1ndez , H. Ho , R. J. Miller , P. Papotti , and L. Popa . Nested Mappings: Schema Mapping Reloaded . In VLDB , pages 67 -- 78 , 2006 . A. Fuxman, M. A. Hern\u00e1ndez, H. Ho, R. J. Miller, P. Papotti, and L. Popa. Nested Mappings: Schema Mapping Reloaded. In VLDB, pages 67--78, 2006."},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/1346330.1346334"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1145\/1066157.1066252"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/543613.543644"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1145\/1559845.1559914"},{"key":"e_1_2_1_13_1","doi-asserted-by":"crossref","DOI":"10.1007\/s007780100048","article-title":"MiniCon: A Scalable Algorithm for Answering Queries using Views","author":"Pottinger R.","year":"2001","unstructured":"R. Pottinger and A. Halevy . MiniCon: A Scalable Algorithm for Answering Queries using Views . VLDB Journal, 10(2--3):182--198 , 2001 . R. Pottinger and A. Halevy. MiniCon: A Scalable Algorithm for Answering Queries using Views. VLDB Journal, 10(2--3):182--198, 2001.","journal-title":"VLDB Journal, 10(2--3):182--198"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1145\/320544.320549"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1145\/1514894.1514903"}],"container-title":["Proceedings of the VLDB Endowment"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.14778\/1687627.1687741","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,28]],"date-time":"2022-12-28T11:34:24Z","timestamp":1672227264000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.14778\/1687627.1687741"}},"subtitle":["computing the core with SQL queries"],"short-title":[],"issued":{"date-parts":[[2009,8]]},"references-count":15,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2009,8]]}},"alternative-id":["10.14778\/1687627.1687741"],"URL":"https:\/\/doi.org\/10.14778\/1687627.1687741","relation":{},"ISSN":["2150-8097"],"issn-type":[{"value":"2150-8097","type":"print"}],"subject":[],"published":{"date-parts":[[2009,8]]}}}