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approx_count()

Estimate the number of times a value appears from a `CountMinSketch`

Early access 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