approx_count()

Estimate the number of times a value appears from a CountMinSketch

Early access Since 1.8.0

Estimate the number of times a given text value appears in a column.

Samples

Given a table of stock data, estimate how many times the symbol AAPL appears:

WITH t AS (
  SELECT toolkit_experimental.count_min_sketch(symbol, 0.01, 0.01) AS symbol_sketch
  FROM crypto_ticks
)
SELECT toolkit_experimental.approx_count('AAPL', symbol_sketch)
FROM t;

Arguments

The syntax is:

approx_count (
    item TEXT,
    agg CountMinSketch
) RETURNS BIGINT

Name	Type	Default	Required	Description
item	TEXT	-	✔	The value you want to estimate occurrences of
agg	CountMinSketch	-	✔	A CountMinSketch object created using count_min_sketch

Returns

Column	Type	Description
approx_count	BIGINT	The estimated number of times item appeared in the sketch