Show table persistence in psql's \dt+ and related commands.

In verbose mode, listTables() now emits a "Persistence" column
showing whether the table/index/view/etc is permanent, temporary,
or unlogged.

David Fetter, reviewed by Fabien Coelho and Rafia Sabih

Discussion: https://postgr.es/m/20190423005642.GZ28936@fetter.org

src/bin/psql/describe.c

@@ -3632,7 +3632,8 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 	PQExpBufferData buf;
 	PGresult   *res;
 	printQueryOpt myopt = pset.popt;
-	static const bool translate_columns[] = {false, false, true, false, false, false, false};
+	int			cols_so_far;
+	bool		translate_columns[] = {false, false, true, false, false, false, false, false};
 
 	/* If tabtypes is empty, we default to \dtvmsE (but see also command.c) */
 	if (!(showTables || showIndexes || showViews || showMatViews || showSeq || showForeign))
@@ -3672,14 +3673,39 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 					  gettext_noop("partitioned index"),
 					  gettext_noop("Type"),
 					  gettext_noop("Owner"));
+	cols_so_far = 4;
 
 	if (showIndexes)
+	{
 		appendPQExpBuffer(&buf,
 						  ",\n  c2.relname as \"%s\"",
 						  gettext_noop("Table"));
+		cols_so_far++;
+	}
 
 	if (verbose)
 	{
+		/*
+		 * Show whether a relation is permanent, temporary, or unlogged.  Like
+		 * describeOneTableDetails(), we consider that persistence emerged in
+		 * v9.1, even though related concepts existed before.
+		 */
+		if (pset.sversion >= 90100)
+		{
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE c.relpersistence WHEN 'p' THEN '%s' WHEN 't' THEN '%s' WHEN 'u' THEN '%s' END as \"%s\"",
+							  gettext_noop("permanent"),
+							  gettext_noop("temporary"),
+							  gettext_noop("unlogged"),
+							  gettext_noop("Persistence"));
+			translate_columns[cols_so_far] = true;
+		}
+
+		/*
+		 * We don't bother to count cols_so_far below here, as there's no need
+		 * to; this might change with future additions to the output columns.
+		 */
+
 		/*
 		 * As of PostgreSQL 9.0, use pg_table_size() to show a more accurate
 		 * size of a table, including FSM, VM and TOAST tables.