tsm_system_time

TABLESAMPLE method which accepts time in milliseconds as a limit

https://www.postgresql.org/docs/current/tsm-system-time.html

Overview

Package	Version	Category	License	Language
`tsm_system_time`	`1.0`	FUNC	PostgreSQL	C

ID	Extension	Bin	Lib	Load	Create	Trust	Reloc	Schema
4890	`tsm_system_time`	No	Yes	No	Yes	Yes	No	-

Related	`faker` `dbt2` `random` `tsm_system_rows` `pg_mockable` `pgsqlmock` `pgtap` `omni_test`

Version

PG18	PG17	PG16	PG15	PG14
1.0	1.0	1.0	1.0	1.0

Install

Note: This is a built-in contrib extension of PostgreSQL

CREATE EXTENSION tsm_system_time;

Usage

tsm_system_time: time-based TABLESAMPLE method

Provides the SYSTEM_TIME table sampling method that returns as many rows as can be read within a specified time limit.

CREATE EXTENSION tsm_system_time;

TABLESAMPLE Method

SYSTEM_TIME(milliseconds float) – maximum time to spend reading the table.

Examples

-- Sample rows readable within 1 second
SELECT * FROM my_table TABLESAMPLE SYSTEM_TIME(1000);

-- Sample from a large table with a 500ms budget
SELECT count(*) FROM large_table TABLESAMPLE SYSTEM_TIME(500);

Performs block-level sampling (not row-level). If the entire table can be read within the time limit, all rows are returned. Does not support REPEATABLE.