4141f08f-347b-4777-9656-e4f01c1fbec620210607030643391naun:naunmdt@crossref.orgMDT DepositInternational Journal of Pure Mathematics2313-057110.46300/91019http://www.naun.org/cms.action?id=6985292021292021810.46300/91019.2021.8https://www.naun.org/cms.action?id=23293IrynaLysenkoNizhyn Gogol State University, Grafska Str. 2, 16600 Nizhyn, UkraineThe paper is focused on some theoretical questions of the table databases. Two mathematical formalisms such as table algebra of infinite tables and multiset table algebra are considered. Basic definitions referring to these formalisms are given. This paper also addresses the issue of the relationship between table algebra of infinite tables and multiset table algebra. It is proved that table algebra of infinite tables is not a subalgebra of multiset table algebra since it is not closed in relation to some signature operations of multiset table algebra. These signature operations are determined.6720216720213437https://www.naun.org/main/NAUN/puremath/2021/a082019-004(2021).pdf10.46300/91019.2021.8.4https://www.naun.org/main/NAUN/puremath/2021/a082019-004(2021).pdfRedko, V., Buy, D., Brona J., Polyakov S.: Relational Databases: Table Algebras and SQL-like Language. Publishing house Academperiodica, Kyiv (2001). Buy, D., Glushko, I.: Calculi and extensions of table algebras signature. NDU im. M. Gogol, Nizhyn (2016). Buy, D., Bogatyreva, J.: Multiset’s theory: bibliography, application in table data bases theory. Radioelectronic and computer systems. Journal 7, 56–61 (2010). 10.15407/pp2018.02.158Glushko, I.: About relationship between table algebra of infinite tables and multiset table algebra. In 11th International Conference of Programming on Proceedings, pp.159–163. CEUR Workshop Proceedings (2018), http://ceur-ws.org/Vol-2139/159-163.pdf. Cutland, N.: Computability. An introduction to recursive function theory. Myr, Moscow (1983).