eriväärtused

Eriväärtused, often translated as "distinct values" or "unique values," is a concept used in data analysis and database management to refer to the set of unique entries within a given column or field. When analyzing a dataset, identifying the eriväärtused is a common first step. This process helps understand the variety of data present, identify potential errors, and prepare data for further processing such as aggregation or feature engineering.

For example, if a dataset contains a column named "Country," the eriväärtused would be the list of all distinct countries represented in that column, such as "USA," "Canada," "Mexico," and so on, without any duplicates. The number of eriväärtused is often referred to as the cardinality of the column. A column with a high number of eriväärtused has high cardinality, while a column with few eriväärtused has low cardinality. Understanding cardinality is crucial for choosing appropriate data storage and processing techniques.

In relational databases, functions like `DISTINCT` in SQL are used to retrieve the eriväärtused from a specific column. This operation is fundamental for data profiling and quality checks. It can reveal inconsistencies, such as different spellings for the same entity (e.g., "New York" and "NY") or unexpected entries. Identifying and handling these eriväärtused is a key part of the data cleaning process, ensuring the accuracy and reliability of subsequent analyses.