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ololobus / create-and-fill-up-table.sql

Last active March 12, 2025 17:35

Create large ~1 GB random dataset in PostgreSQL

	CREATE TABLE large_test (num1 bigint, num2 double precision, num3 double precision);

	INSERT INTO large_test (num1, num2, num3)
	SELECT round(random()10), random(), random()142
	FROM generate_series(1, 20000000) s(i);

	EXPLAIN (analyse, buffers)
	SELECT num1, avg(num3) as num3_avg, sum(num2) as num2_sum
	FROM large_test
	GROUP BY num1;