omnisketch

pig build pkg omnisketch;		# build rpm/deb

pig repo add pgsql -u   # add both repo and update cache

pig install omnisketch;		# install via package name, for the active PG version

pig install omnisketch -v 18;   # install for PG 18
pig install omnisketch -v 17;   # install for PG 17
pig install omnisketch -v 16;   # install for PG 16
pig install omnisketch -v 15;   # install for PG 15
pig install omnisketch -v 14;   # install for PG 14

CREATE EXTENSION omnisketch;

CREATE EXTENSION omnisketch;

-- Create sample data
CREATE TABLE data (id INT, a INT, b INT);
INSERT INTO data SELECT i, mod(i,100), mod(i,100) FROM generate_series(1,1000000) s(i);

-- Pre-calculate sketches on partitions
CREATE TABLE sketches AS
SELECT mod(id,10) AS p, omnisketch(0.01, 0.01, (a, b)) AS s
FROM data GROUP BY mod(id,10);

-- Estimate count for condition (a = 10 AND b = 10)
SELECT omnisketch_estimate(omnisketch(s), (10, 10)) FROM sketches;

-- Get total record count
SELECT omnisketch_count(omnisketch(s)) FROM sketches;