/usr/share/postgresql/9.5/extension/prefix--1.1--1.2.0.sql is in postgresql-9.5-prefix 1.2.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 | -- complain if script is sourced in psql, rather than via CREATE EXTENSION
\echo Use "ALTER EXTENSION prefix UPDATE TO '1.2.0'" to load this file. \quit
-- version 1.2.0 adds restrict and join properties to the operator <@
-- (prefix_range, prefix_range), but don't automatically update that here:
--
-- due to dependencies, that would mean dropping all your prefix_range
-- columns and having to install the extension all over again. please
-- consider doing so yourself if you need it.
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