Find the second-highest distinct value.

Postgres: Select the maximum below the overall maximum to skip ties at the top.

SQL snippet.sql
CREATE TABLE sales (id INTEGER PRIMARY KEY, team VARCHAR(10), amount INTEGER, units INTEGER);
INSERT INTO sales VALUES (1,'A',10,2),(2,'A',20,1),(3,'B',30,3),(4,'B',40,2);
SELECT MAX(amount) FROM sales WHERE amount<(SELECT MAX(amount) FROM sales);

Expected output EXAMPLE

30

Details

Requires PostgreSQL 18. Run in an empty scratch schema using psql or a SQL client. Result rows below use | between columns, without headers; client display formatting may differ. Select the maximum below the overall maximum to skip ties at the top. The CREATE and INSERT statements provide all input data. Run the complete example in a fresh scratch database or schema.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · PostgreSQL 18.6 (Debian 18.6-1.pgdg13+2) · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3; psycopg 3.2.10; pymssql 2.3.8

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Database services use a private internal Docker network without published ports. Fresh scratch schema/database for each case; test database administrator credentials are confined to these disposable services. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel
x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale
uid=65534, gid=65534 (unprivileged process) / C.UTF-8
Interpreter invocation
Execute the exact SQL in a fresh database/schema; serialize result rows with | separators
Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3
Code SHA-256
ef7052cdf421e89b2445b12f244b61749814b8b9caaa2d9726818c85748fe11f
Dependencies
bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3; psycopg 3.2.10; pymssql 2.3.8

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

30

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.