Generate test data ​

Use generate_series as a row source for a repeatable test table. Its bounds are inclusive, and expressions can derive other columns from the generated value.

Create a fixture ​

CREATE TABLE samples(id INTEGER PRIMARY KEY, value INTEGER);
INSERT INTO samples
SELECT generate_series, generate_series * 10
FROM generate_series(1, 100);

Verify the shape ​

SELECT count(*) AS rows, min(value), max(value), sum(value)
FROM samples
FORMAT csv;

100,10,1000,50500

The fixture has stable values and no dependence on random state. A descending series needs a negative step; zero is an error. NULL bounds or an unreachable direction produce no rows.

Use a data distribution representative of the query being tested when comparing plans or timings. A small sequential fixture verifies behavior but does not establish performance on a different workload.

See generate_series for numeric and calendar inputs.