May 16, 2012 · Could somebody explain to me, with the help of examples, what is cardinality in databases?

Aug 28, 2014 · High-cardinality - many tuples, low-cardinality - few tuples. While the Wikipedia article on Cardinality (SQL statements), defines it as follows: Cardinality refers to the …

对于数据库而言，索引应该尽量选择高选择性的，所以必须重视 Cardinality （基数）值。 Cardinality 指的是一个列中不同值的个数。 最大索引意味着某个列的每个值都是唯一的，比如 …

May 7, 2022 · When talking about data models and databases, the term Cardinality is often used to describe the number of allowed elements in a given set. UML often refers to the same …

Jul 18, 2013 · I would like to know once and for all how to write UML cardinalities, since I very often had to debate about them (so proofs and sources are very welcome :) If I want to explain …

Apr 20, 2023 · Table cardinality refers to the relationship between two tables in a database, which specifies how many records in one table can be associated with one or more records in …

Dec 23, 2015 · The cardinality at the end of a line tells you for a given entity instance how many relationship instances/rows it can appear in. If a given instance/value doesn't have to appear …

Aug 3, 2010 · In database design what do n:m and 1:n mean? Does it have anything to do with keys or relationships?

Dec 2, 2014 · Cardinality is minimum and maximun number of entity occurrence associated with one occurrence of the related entity cardinality types as 1 to 1 , 1 to many , many to many. or …

Please look at this query plan If cardinality estimate was affected by the conversion, then estimated number of rows would be significantly different than actual number of rows, but they …