Searching on a single search term with all defaults except "Search within" changed to 'Topic titles only' or "First post of topics only" will fail with this message:

SQL ERROR [ postgres ]

ERROR: missing FROM-clause entry for table "t" LINE 1: ...s p ON (m0.post_id = p.post_id) WHERE p.post_id = t.topic_fi... ^ []

SQL

SELECT COUNT(DISTINCT p.post_id) as total_results FROM phpbb_search_wordmatch m0 LEFT JOIN phpbb_posts p ON (m0.post_id = p.post_id) WHERE p.post_id = t.topic_first_post_id AND m0.word_id = 66526 AND m0.title_match = 1

BACKTRACE

FILE: includes/db/postgres.php
LINE: 177
CALL: dbal->sql_error()

FILE: includes/search/fulltext_native.php
LINE: 663
CALL: dbal_postgres->sql_query()

FILE: search.php
LINE: 418
CALL: fulltext_native->keyword_search()