{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T10:05:42Z","timestamp":1773655542506,"version":"3.50.1"},"reference-count":9,"publisher":"Association for Computing Machinery (ACM)","issue":"12","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Proc. VLDB Endow."],"published-print":{"date-parts":[[2021,7]]},"abstract":"<jats:p>The variety of data is one of the important issues in the era of Big Data. The data are naturally organized in different formats and models, including structured data, semi-structured data, and unstructured data. Prior research has envisioned an approach to abstract multi-model data with a schema category and an instance category by using category theory. In this paper, we demonstrate a system, called MultiCategory, which processes multi-model queries based on category theory and functional programming. This demo is centered around four main scenarios to show a tangible system. First, we show how to build a schema category and an instance category by loading different models of data, including relational, XML, key-value, and graph data. Second, we show a few examples of query processing by using the functional programming language Haskell. Third, we demo the flexible outputs with different models of data for the same input query. Fourth, to better understand the category theoretical structure behind the queries, we offer a variety of graphical hooks to explore and visualize queries as graphs with respect to the schema category, as well as the query processing procedure with Haskell.<\/jats:p>","DOI":"10.14778\/3476311.3476314","type":"journal-article","created":{"date-parts":[[2021,10,28]],"date-time":"2021-10-28T22:48:43Z","timestamp":1635461323000},"page":"2663-2666","source":"Crossref","is-referenced-by-count":4,"title":["MultiCategory"],"prefix":"10.14778","volume":"14","author":[{"given":"Valter","family":"Uotila","sequence":"first","affiliation":[{"name":"University of Helsinki"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiaheng","family":"Lu","sequence":"additional","affiliation":[{"name":"University of Helsinki"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dieter","family":"Gawlick","sequence":"additional","affiliation":[{"name":"Oracle Corporation"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhen Hua","family":"Liu","sequence":"additional","affiliation":[{"name":"Oracle Corporation"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Souripriya","family":"Das","sequence":"additional","affiliation":[{"name":"Oracle Corporation"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gregory","family":"Pogossiants","sequence":"additional","affiliation":[{"name":"SATS Technologies"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2021,10,28]]},"reference":[{"key":"e_1_2_1_1_1","doi-asserted-by":"crossref","unstructured":"Torsten Grust. 1999. Comprehending Queries. Ph.D. Dissertation. Universitaet Konstanz Konstanz.  Torsten Grust. 1999. Comprehending Queries . Ph.D. Dissertation. Universitaet Konstanz Konstanz.","DOI":"10.1007\/978-3-322-84823-9_7"},{"key":"e_1_2_1_2_1","volume-title":"Multi-model Database Management Systems - A Look Forward. In Polystores VLDB 2018 Workshops. 16--29","author":"Liu Zhen Hua","year":"2018","unstructured":"Zhen Hua Liu , Jiaheng Lu , Dieter Gawlick , Heli Helskyaho , Gregory Pogossiants , and Zhe Wu . 2018 . Multi-model Database Management Systems - A Look Forward. In Polystores VLDB 2018 Workshops. 16--29 . Zhen Hua Liu, Jiaheng Lu, Dieter Gawlick, Heli Helskyaho, Gregory Pogossiants, and Zhe Wu. 2018. Multi-model Database Management Systems - A Look Forward. In Polystores VLDB 2018 Workshops. 16--29."},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1145\/3323214"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4612-9839-7"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1145\/3156695.3122956"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.5555\/2628001"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ic.2012.05.001"},{"key":"e_1_2_1_8_1","volume-title":"Accessed","author":"Uotila Valter","year":"2021","unstructured":"Valter Uotila . 2021 . MultiCategory Documentation and System Codes. https:\/\/multicategory.github.io\/, https:\/\/git.io\/JvPqM . Accessed Jul. 19, 2021. Valter Uotila. 2021. MultiCategory Documentation and System Codes. https:\/\/multicategory.github.io\/, https:\/\/git.io\/JvPqM. Accessed Jul. 19, 2021."},{"key":"e_1_2_1_9_1","volume-title":"Accessed","author":"Uotila Valter","year":"2021","unstructured":"Valter Uotila and Jiaheng Lu . 2021 . MultiCategory demo video. https:\/\/youtu.be\/uceIi91AGsg . Accessed Jul. 19, 2021. Valter Uotila and Jiaheng Lu. 2021. MultiCategory demo video. https:\/\/youtu.be\/uceIi91AGsg. Accessed Jul. 19, 2021."}],"container-title":["Proceedings of the VLDB Endowment"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.14778\/3476311.3476314","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,28]],"date-time":"2022-12-28T11:26:41Z","timestamp":1672226801000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.14778\/3476311.3476314"}},"subtitle":["multi-model query processing meets category theory and functional programming"],"short-title":[],"issued":{"date-parts":[[2021,7]]},"references-count":9,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2021,7]]}},"alternative-id":["10.14778\/3476311.3476314"],"URL":"https:\/\/doi.org\/10.14778\/3476311.3476314","relation":{},"ISSN":["2150-8097"],"issn-type":[{"value":"2150-8097","type":"print"}],"subject":[],"published":{"date-parts":[[2021,7]]}}}