This page is a quick reference checkpoint for FIRST VALUE in Postgres: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
FIRST_VALUE returns the first value in the window frame.
Returns the value of the first row in the window frame; behavior depends on the frame clause (default frame may not cover the entire partition).
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
FIRST_VALUE(value) is listed as a window function and requires an OVER clause.
SELECT FIRST_VALUE(salary) OVER (ORDER BY salary) FROM empsalary;
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
FIRST VALUE is part of a bigger window-function pattern. If you want the “why”, start here: First Last Nth Value
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View Postgres Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.