Skip to main content
Skip to main content

uniqExact

Calculates the exact number of different argument values.

Use the uniqExact function if you absolutely need an exact result. Otherwise use the uniq function.

The uniqExact function uses more memory than uniq, because the size of the state has unbounded growth as the number of different values increases.

Arguments

The function takes a variable number of parameters. Parameters can be Tuple, Array, Date, DateTime, String, or numeric types.

Example

In this example we'll use the uniqExact function to count the number of unique type codes (a short identifier for the type of aircraft) in the opensky data set.

See Also

Try ClickHouse Cloud for FREE

Separation of storage and compute, automatic scaling, built-in SQL console, and lots more. $300 in free credits when signing up.

Try it for Free