In the context of Azure Synapse, what does the term "cardinality" refer to?

Cardinality in the context of Azure Synapse refers specifically to the number of unique values in a column of a dataset. This concept is crucial when it comes to database optimization and design, as understanding the cardinality of data can help in indexing strategies, query performance, and choosing the appropriate data types. High cardinality indicates a greater variety of unique values, while low cardinality signifies that there are fewer unique values compared to the total number of entries in that column. This insight is essential for data engineers when analyzing and optimizing data storage and retrieval in Azure Synapse.