--- a/inc/functions_search.php
+++ b/inc/functions_search.php
@@ -1802,3 +1802,555 @@ function perform_search_mysql_ft($search)
 	);
 }
+
+/**
+ * Clean search keywords for PostgreSQL fulltext searching, converting user input
+ * into valid tsquery syntax.
+ *
+ * Translates boolean operators:
+ *   "and" => &, "or" => |, "not" => !
+ * Handles quoted phrases using the followed-by operator (<->).
+ * Supports wildcard prefix matching with :* suffix.
+ * Falls back gracefully on malformed input.
+ *
+ * @param string $keywords The raw keywords from user input
+ * @return string|bool The cleaned tsquery string or false on failure
+ */
+function clean_keywords_ft_pgsql($keywords)
+{
+	if(!$keywords)
+	{
+		return false;
+	}
+
+	$keywords = my_strtolower($keywords);
+	$keywords = preg_replace("#\*{2,}#s", "*", $keywords);
+	// Remove characters that are problematic in tsquery syntax
+	$keywords = preg_replace("#([\[\]\|\.\,\:\;\!\&\(\)])#s", " ", $keywords);
+	$keywords = preg_replace("#\s+#s", " ", $keywords);
+	$keywords = trim($keywords);
+
+	if(!$keywords)
+	{
+		return false;
+	}
+
+	global $mybb;
+
+	$min_word_length = (int)$mybb->settings['minsearchword'];
+	if($min_word_length <= 0)
+	{
+		$min_word_length = 3;
+	}
+
+	// Split on double quotes to identify phrases vs. free terms
+	$segments = explode('"', $keywords);
+	$inquote = false;
+	$tsquery_parts = array();
+	$pending_operator = '&'; // default boolean between terms
+
+	foreach($segments as $segment)
+	{
+		$segment = trim($segment);
+		if($segment === '')
+		{
+			$inquote = !$inquote;
+			continue;
+		}
+
+		if($inquote)
+		{
+			// Quoted phrase: join words with the followed-by operator <->
+			$phrase_words = preg_split("#\s+#", $segment);
+			$valid_phrase_words = array();
+			foreach($phrase_words as $pw)
+			{
+				$pw = preg_replace("#[^a-z0-9_*]#", '', $pw);
+				if($pw === '' || my_strlen(str_replace('*', '', $pw)) < $min_word_length)
+				{
+					continue;
+				}
+				// Convert trailing wildcard * to PostgreSQL prefix match :*
+				if(substr($pw, -1) === '*')
+				{
+					$pw = substr($pw, 0, -1).':*';
+				}
+				$valid_phrase_words[] = "'" . $pw . "'";
+			}
+			if(!empty($valid_phrase_words))
+			{
+				$phrase_tsquery = implode(' <-> ', $valid_phrase_words);
+				if(count($valid_phrase_words) > 1)
+				{
+					$phrase_tsquery = '(' . $phrase_tsquery . ')';
+				}
+				if(!empty($tsquery_parts))
+				{
+					$tsquery_parts[] = $pending_operator;
+					$pending_operator = '&';
+				}
+				$tsquery_parts[] = $phrase_tsquery;
+			}
+		}
+		else
+		{
+			// Non-quoted segment: split into words and handle boolean operators
+			$words = preg_split("#\s+#", $segment);
+			foreach($words as $word)
+			{
+				$word = trim($word);
+				if($word === '')
+				{
+					continue;
+				}
+
+				// Check for boolean operators
+				if($word === 'and')
+				{
+					$pending_operator = '&';
+					continue;
+				}
+				elseif($word === 'or')
+				{
+					$pending_operator = '|';
+					continue;
+				}
+				elseif($word === 'not')
+				{
+					// NOT modifies the next term
+					if(!empty($tsquery_parts))
+					{
+						$tsquery_parts[] = '&';
+					}
+					$tsquery_parts[] = '!';
+					$pending_operator = '';
+					continue;
+				}
+
+				// Check for leading +/- operators from user input
+				$negate = false;
+				if(substr($word, 0, 1) === '-')
+				{
+					$negate = true;
+					$word = substr($word, 1);
+				}
+				elseif(substr($word, 0, 1) === '+')
+				{
+					$word = substr($word, 1);
+				}
+
+				// Strip any remaining special characters
+				$word = preg_replace("#[^a-z0-9_*]#", '', $word);
+				$bare_word = str_replace('*', '', $word);
+
+				if($bare_word === '' || my_strlen($bare_word) < $min_word_length)
+				{
+					continue;
+				}
+
+				// Convert trailing wildcard * to PostgreSQL prefix match :*
+				if(substr($word, -1) === '*')
+				{
+					$word = substr($word, 0, -1).':*';
+				}
+
+				$term = "'" . $word . "'";
+
+				if($negate)
+				{
+					if(!empty($tsquery_parts) && $pending_operator !== '')
+					{
+						$tsquery_parts[] = $pending_operator;
+					}
+					elseif(!empty($tsquery_parts))
+					{
+						$tsquery_parts[] = '&';
+					}
+					$tsquery_parts[] = '!' . $term;
+					$pending_operator = '&';
+				}
+				else
+				{
+					if(!empty($tsquery_parts) && $pending_operator !== '')
+					{
+						$tsquery_parts[] = $pending_operator;
+					}
+					elseif(!empty($tsquery_parts))
+					{
+						$tsquery_parts[] = '&';
+					}
+					$tsquery_parts[] = $term;
+					$pending_operator = '&';
+				}
+			}
+		}
+
+		$inquote = !$inquote;
+	}
+
+	if(empty($tsquery_parts))
+	{
+		return false;
+	}
+
+	$tsquery = implode(' ', $tsquery_parts);
+
+	// Clean up any malformed operator sequences (e.g., "& &", "& |", trailing operators)
+	$tsquery = preg_replace("#(\s*[&|!]\s*){2,}#", ' & ', $tsquery);
+	$tsquery = preg_replace("#^\s*[&|]\s*#", '', $tsquery);
+	$tsquery = preg_replace("#\s*[&|]\s*$#", '', $tsquery);
+	$tsquery = trim($tsquery);
+
+	if(!$tsquery || $tsquery === '!' || $tsquery === '&' || $tsquery === '|')
+	{
+		return false;
+	}
+
+	return $tsquery;
+}
+
+/**
+ * Perform a thread and post search under PostgreSQL using native fulltext search
+ * capabilities (tsvector/tsquery with GIN indexes).
+ *
+ * This function mirrors the structure of perform_search_mysql_ft() but generates
+ * PostgreSQL-compatible fulltext query clauses using to_tsvector() @@ to_tsquery().
+ *
+ * The text search configuration defaults to 'english' but can be overridden via
+ * the $mybb->settings['pgsql_fts_config'] setting.
+ *
+ * Recommended GIN indexes for performance:
+ *   CREATE INDEX idx_posts_message_fts ON mybb_posts USING gin(to_tsvector('english', message));
+ *   CREATE INDEX idx_posts_subject_fts ON mybb_posts USING gin(to_tsvector('english', subject));
+ *   CREATE INDEX idx_threads_subject_fts ON mybb_threads USING gin(to_tsvector('english', subject));
+ *
+ * @param array $search Array of search data
+ * @return array Array of search data with results mixed in
+ */
+function perform_search_pgsql_ft($search)
+{
+	global $mybb, $db, $lang;
+
+	$keywords = clean_keywords_ft_pgsql($search['keywords']);
+
+	if($mybb->settings['minsearchword'] < 1)
+	{
+		$mybb->settings['minsearchword'] = 3;
+	}
+
+	// Determine the PostgreSQL text search configuration to use
+	$ts_config = 'english';
+	if(!empty($mybb->settings['pgsql_fts_config']))
+	{
+		// Sanitize: only allow alphanumeric and underscore
+		$ts_config = preg_replace("#[^a-z0-9_]#i", '', $mybb->settings['pgsql_fts_config']);
+		if(empty($ts_config))
+		{
+			$ts_config = 'english';
+		}
+	}
+
+	$message_lookin = $subject_lookin = '';
+	if($keywords)
+	{
+		// Validate keyword lengths (same approach as MySQL FT)
+		$keywords_for_check = preg_replace("#[':*!&|<>()\-\s]#", ' ', $keywords);
+		$check_words = preg_split("#\s+#", trim($keywords_for_check));
+		$all_too_short = true;
+		foreach($check_words as $word)
+		{
+			if($word !== '' && my_strlen($word) >= $mybb->settings['minsearchword'])
+			{
+				$all_too_short = false;
+				break;
+			}
+		}
+
+		if($all_too_short)
+		{
+			$lang->error_minsearchlength = $lang->sprintf($lang->error_minsearchlength, $mybb->settings['minsearchword']);
+			error($lang->error_minsearchlength);
+		}
+
+		$escaped_keywords = $db->escape_string($keywords);
+		$message_lookin = "AND to_tsvector('{$ts_config}', p.message) @@ to_tsquery('{$ts_config}', '{$escaped_keywords}')";
+		$subject_lookin = "AND to_tsvector('{$ts_config}', t.subject) @@ to_tsquery('{$ts_config}', '{$escaped_keywords}')";
+	}
+
+	$post_usersql = '';
+	$thread_usersql = '';
+	if(!empty($search['author']))
+	{
+		$userids = array();
+		$search['author'] = my_strtolower($search['author']);
+		if($search['matchusername'])
+		{
+			$user = get_user_by_username($search['author']);
+			if($user)
+			{
+				$userids[] = $user['uid'];
+			}
+		}
+		else
+		{
+			$query = $db->simple_select("users", "uid", "LOWER(username) LIKE '%".$db->escape_string_like($search['author'])."%'");
+			while($user = $db->fetch_array($query))
+			{
+				$userids[] = $user['uid'];
+			}
+		}
+
+		if(count($userids) < 1)
+		{
+			error($lang->error_nosearchresults);
+		}
+		else
+		{
+			$userids = implode(',', $userids);
+			$post_usersql = " AND p.uid IN (".$userids.")";
+			$thread_usersql = " AND t.uid IN (".$userids.")";
+		}
+	}
+
+	$datecut = $thread_datecut = $post_datecut = '';
+	if(!empty($search['postdate']))
+	{
+		if($search['pddir'] == 0)
+		{
+			$datecut = "<=";
+		}
+		else
+		{
+			$datecut = ">=";
+		}
+		$now = TIME_NOW;
+		$datelimit = $now-(86400 * $search['postdate']);
+		$datecut .= "'$datelimit'";
+		$post_datecut = " AND p.dateline $datecut";
+		$thread_datecut = " AND t.dateline $datecut";
+	}
+
+	$thread_replycut = '';
+	if(!empty($search['numreplies']) && $search['findthreadst'])
+	{
+		if((int)$search['findthreadst'] == 1)
+		{
+			$thread_replycut = " AND t.replies >= '".(int)$search['numreplies']."'";
+		}
+		else
+		{
+			$thread_replycut = " AND t.replies <= '".(int)$search['numreplies']."'";
+		}
+	}
+
+	$thread_prefixcut = '';
+	$prefixlist = array();
+	if(!empty($search['threadprefix']) && $search['threadprefix'][0] != 'any')
+	{
+		foreach($search['threadprefix'] as $threadprefix)
+		{
+			$threadprefix = (int)$threadprefix;
+			$prefixlist[] = $threadprefix;
+		}
+	}
+	if(count($prefixlist) == 1)
+	{
+		$thread_prefixcut .= " AND t.prefix='$threadprefix' ";
+	}
+	else
+	{
+		if(count($prefixlist) > 1)
+		{
+			$thread_prefixcut = " AND t.prefix IN (".implode(',', $prefixlist).")";
+		}
+	}
+
+	$forumin = '';
+	$fidlist = array();
+	if(!empty($search['forums']) && (!is_array($search['forums']) || $search['forums'][0] != "all"))
+	{
+		if(!is_array($search['forums']))
+		{
+			$search['forums'] = array((int)$search['forums']);
+		}
+		foreach($search['forums'] as $forum)
+		{
+			$forum = (int)$forum;
+			if($forum > 0)
+			{
+				$fidlist[] = $forum;
+				$child_list = get_child_list($forum);
+				if(is_array($child_list))
+				{
+					$fidlist = array_merge($fidlist, $child_list);
+				}
+			}
+		}
+		$fidlist = array_unique($fidlist);
+		if(count($fidlist) >= 1)
+		{
+			$forumin = " AND t.fid IN (".implode(',', $fidlist).")";
+		}
+	}
+
+	$permsql = "";
+	$onlyusfids = array();
+
+	// Check group permissions if we can't view threads not started by us
+	$group_permissions = forum_permissions();
+	foreach($group_permissions as $fid => $forum_permissions)
+	{
+		if(isset($forum_permissions['canonlyviewownthreads']) && $forum_permissions['canonlyviewownthreads'] == 1)
+		{
+			$onlyusfids[] = $fid;
+		}
+	}
+	if(!empty($onlyusfids))
+	{
+		$permsql .= "AND ((t.fid IN(".implode(',', $onlyusfids).") AND t.uid='{$mybb->user['uid']}') OR t.fid NOT IN(".implode(',', $onlyusfids)."))";
+	}
+
+	$unsearchforums = get_unsearchable_forums();
+	if($unsearchforums)
+	{
+		$permsql .= " AND t.fid NOT IN ($unsearchforums)";
+	}
+	$inactiveforums = get_inactive_forums();
+	if($inactiveforums)
+	{
+		$permsql .= " AND t.fid NOT IN ($inactiveforums)";
+	}
+
+	$visiblesql = $post_visiblesql = $plain_post_visiblesql = "";
+	if(isset($search['visible']))
+	{
+		if($search['visible'] == 1)
+		{
+			$visiblesql = " AND t.visible = '1'";
+			if($search['postthread'] == 1)
+			{
+				$post_visiblesql = " AND p.visible = '1'";
+				$plain_post_visiblesql = " AND visible = '1'";
+			}
+		}
+		elseif($search['visible'] == -1)
+		{
+			$visiblesql = " AND t.visible = '-1'";
+			if($search['postthread'] == 1)
+			{
+				$post_visiblesql = " AND p.visible = '-1'";
+				$plain_post_visiblesql = " AND visible = '-1'";
+			}
+		}
+		else
+		{
+			$visiblesql = " AND t.visible != '1'";
+			if($search['postthread'] == 1)
+			{
+				$post_visiblesql = " AND p.visible != '1'";
+				$plain_post_visiblesql = " AND visible != '1'";
+			}
+		}
+	}
+
+	// Moderators can view unapproved threads and deleted threads from forums they moderate
+	$unapproved_where_t = get_visible_where('t');
+	$unapproved_where_p = get_visible_where('p');
+
+	// Searching a specific thread?
+	$tidsql = '';
+	if(!empty($search['tid']))
+	{
+		$tidsql = " AND t.tid='".(int)$search['tid']."'";
+	}
+
+	$limitsql = '';
+	if((int)$mybb->settings['searchhardlimit'] > 0)
+	{
+		$limitsql = "LIMIT ".(int)$mybb->settings['searchhardlimit'];
+	}
+
+	// Searching both posts and thread titles
+	$threads = array();
+	$posts = array();
+	$firstposts = array();
+	if($search['postthread'] == 1)
+	{
+		// No need to search subjects when looking for results within a specific thread
+		if(empty($search['tid']))
+		{
+			$query = $db->query("
+				SELECT t.tid, t.firstpost
+				FROM ".TABLE_PREFIX."threads t
+				WHERE 1=1 {$thread_datecut} {$thread_replycut} {$thread_prefixcut} {$forumin} {$thread_usersql} {$permsql} {$visiblesql} AND ({$unapproved_where_t}) AND t.closed NOT LIKE 'moved|%' {$subject_lookin}
+				{$limitsql}
+			");
+			while($thread = $db->fetch_array($query))
+			{
+				$threads[$thread['tid']] = $thread['tid'];
+				if($thread['firstpost'])
+				{
+					$posts[$thread['tid']] = $thread['firstpost'];
+				}
+			}
+		}
+
+		$query = $db->query("
+			SELECT p.pid, p.tid
+			FROM ".TABLE_PREFIX."posts p
+			LEFT JOIN ".TABLE_PREFIX."threads t ON (t.tid=p.tid)
+			WHERE 1=1 {$post_datecut} {$thread_replycut} {$thread_prefixcut} {$forumin} {$post_usersql} {$permsql} {$tidsql} {$post_visiblesql} {$visiblesql} AND ({$unapproved_where_t}) AND ({$unapproved_where_p}) AND t.closed NOT LIKE 'moved|%' {$message_lookin}
+			{$limitsql}
+		");
+		while($post = $db->fetch_array($query))
+		{
+			$posts[$post['pid']] = $post['pid'];
+			$threads[$post['tid']] = $post['tid'];
+		}
+		if(count($posts) < 1 && count($threads) < 1)
+		{
+			error($lang->error_nosearchresults);
+		}
+		$threads = implode(',', $threads);
+		$posts = implode(',', $posts);
+	}
+	// Searching only thread titles
+	else
+	{
+		$query = $db->query("
+			SELECT t.tid, t.firstpost
+			FROM ".TABLE_PREFIX."threads t
+			WHERE 1=1 {$thread_datecut} {$thread_replycut} {$thread_prefixcut} {$forumin} {$thread_usersql} {$permsql} {$visiblesql} AND ({$unapproved_where_t}) {$subject_lookin}
+			{$limitsql}
+		");
+		while($thread = $db->fetch_array($query))
+		{
+			$threads[$thread['tid']] = $thread['tid'];
+			if($thread['firstpost'])
+			{
+				$firstposts[$thread['tid']] = $thread['firstpost'];
+			}
+		}
+		if(count($threads) < 1)
+		{
+			error($lang->error_nosearchresults);
+		}
+
+		$threads = implode(',', $threads);
+		$firstposts = implode(',', $firstposts);
+		if($firstposts)
+		{
+			$query = $db->simple_select("posts", "pid", "pid IN ($firstposts) {$plain_post_visiblesql} {$limitsql}");
+			while($post = $db->fetch_array($query))
+			{
+				$posts[$post['pid']] = $post['pid'];
+			}
+			$posts = implode(',', $posts);
+		}
+	}
+	return array(
+		"threads" => $threads,
+		"posts" => $posts,
+		"querycache" => ''
+	);
+}

--- a/search.php
+++ b/search.php
@@ -1148,7 +1148,11 @@
 	if($db->can_search == true)
 	{
-		if($mybb->settings['searchtype'] == "fulltext" && $db->supports_fulltext_boolean("posts") && $db->is_fulltext("posts"))
+		if($db->type == 'pgsql' && $mybb->settings['searchtype'] == "fulltext")
+		{
+			$search_results = perform_search_pgsql_ft($search_data);
+		}
+		elseif($mybb->settings['searchtype'] == "fulltext" && $db->supports_fulltext_boolean("posts") && $db->is_fulltext("posts"))
 		{
 			$search_results = perform_search_mysql_ft($search_data);
 		}

--- a/inc/db/PostgresPdoDbDriver.php
+++ b/inc/db/PostgresPdoDbDriver.php
@@ -XXX,8 +XXX,34 @@
 	function is_fulltext($table, $index = "")
 	{
-		return false;
+		$tableName = $this->escape_string("{$this->table_prefix}{$table}");
+
+		if($index)
+		{
+			$index = $this->escape_string($index);
+			$query = $this->write_query("
+				SELECT 1
+				FROM pg_indexes
+				WHERE tablename = '{$tableName}'
+				AND indexname = '{$index}'
+				AND indexdef LIKE '%gin%tsvector%'
+				LIMIT 1
+			");
+		}
+		else
+		{
+			$query = $this->write_query("
+				SELECT 1
+				FROM pg_indexes
+				WHERE tablename = '{$tableName}'
+				AND indexdef LIKE '%gin%tsvector%'
+				LIMIT 1
+			");
+		}
+
+		$exists = $this->num_rows($query);
+		return $exists > 0;
 	}
 
 	public function supports_fulltext($table)
 	{
-		return false;
+		return true;
 	}

@@ -XXX,8 +XXX,36 @@
 	public function supports_fulltext_boolean($table)
 	{
-		return false;
+		return true;
 	}
 
 	public function create_fulltext_index($table, $column, $name = "")
 	{
-		return false;
+		global $mybb;
+
+		$tableName = $this->escape_string("{$this->table_prefix}{$table}");
+		$column = $this->escape_string($column);
+
+		if(!$name)
+		{
+			$name = "ft_{$table}_{$column}";
+		}
+		$name = $this->escape_string($name);
+
+		// Determine the text search configuration
+		$ts_config = 'english';
+		if(!empty($mybb->settings['pgsql_fts_config']))
+		{
+			$ts_config = preg_replace("#[^a-z0-9_]#i", '', $mybb->settings['pgsql_fts_config']);
+			if(empty($ts_config))
+			{
+				$ts_config = 'english';
+			}
+		}
+
+		$this->write_query("
+			CREATE INDEX {$name}
+			ON {$tableName}
+			USING gin(to_tsvector('{$ts_config}', {$column}))
+		");
+
+		return true;
 	}

@@ -XXX,6 +XXX,11 @@
 		$this->write_query("
 			ALTER TABLE {$this->table_prefix}{$table}
 			DROP INDEX {$name}
 		");
 	}
+
+	public function drop_fulltext_index($table, $name)
+	{
+		$this->write_query("DROP INDEX IF EXISTS {$this->escape_string($name)}");
+	}