tab_completion_alter_index_wip1.patch

diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 5ba6ffba8c..28f2e9a0f9 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -583,6 +583,18 @@ static const SchemaQuery Query_for_list_of_statistics = {
 "        OR '\"' || relname || '\"'='%s') "\
 "   AND pg_catalog.pg_table_is_visible(c.oid)"
 
+#define Query_for_list_of_attribute_numbers \
+"SELECT attnum "\
+"  FROM pg_catalog.pg_attribute a, "\
+"       pg_catalog.pg_class c "\
+" WHERE c.oid = a.attrelid "\
+"   AND a.attnum > 0 "\
+"   AND NOT a.attisdropped "\
+"   /* %d %s */" \
+"   AND a.attrelid = (select oid from pg_catalog.pg_class where relname = '%s') "\
+"   AND pg_catalog.pg_table_is_visible(c.oid) "\
+"order by a.attnum asc "
+
 #define Query_for_list_of_attributes_with_schema \
 "SELECT pg_catalog.quote_ident(attname) "\
 "  FROM pg_catalog.pg_attribute a, pg_catalog.pg_class c, pg_catalog.pg_namespace n "\
@@ -1566,9 +1578,22 @@ psql_completion(const char *text, int start, int end)
 		COMPLETE_WITH("PARTITION");
 	else if (Matches("ALTER", "INDEX", MatchAny, "ATTACH", "PARTITION"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_indexes, NULL);
-	/* ALTER INDEX <name> ALTER COLUMN <colnum> */
-	else if (Matches("ALTER", "INDEX", MatchAny, "ALTER", "COLUMN", MatchAny))
+	/* ALTER INDEX <name> ALTER COLUMN */
+	else if (Matches("ALTER", "INDEX", MatchAny, "ALTER", "COLUMN") ||
+			 Matches("ALTER", "INDEX", MatchAny, "ALTER"))
+	{
+		completion_info_charp = prev3_wd;
+		COMPLETE_WITH_QUERY(Query_for_list_of_attribute_numbers);
+	}
+	/* ALTER INDEX <name> ALTER COLUMN <col number> */
+	else if (Matches("ALTER", "INDEX", MatchAny, "ALTER", "COLUMN", MatchAny) ||
+			 Matches("ALTER", "INDEX", MatchAny, "ALTER", MatchAny))
 		COMPLETE_WITH("SET STATISTICS");
+	/* ALTER INDEX <name> ALTER COLUMN <col number> SET STATISTICS */
+	else if (HeadMatches("ALTER", "INDEX") && TailMatches("SET", "STATISTICS"))
+	{
+		/* We don't complete after "SET STATISTICS" */
+	}
 	/* ALTER INDEX <name> SET */
 	else if (Matches("ALTER", "INDEX", MatchAny, "SET"))
 		COMPLETE_WITH("(", "TABLESPACE");