check_function_bodies

• 17
• 16
• 15
• 14
• 13
• 12
• 11
• 10
• 9.6
• 9.5
• 9.4
• 9.3
• 9.2
• 9.1
• 9.0
• 8.4
• 8.3
• 8.2

通常情况下，正在创建的函数的主体会被验证

postgres=# CREATE FUNCTION foo()
  RETURNS INT
  LANGUAGE SQL
AS 'SELECT * FROM bar()';
ERROR:  function bar() does not exist
LINE 4: AS 'SELECT * FROM bar()';
                          ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

但是，如果 check_function_bodies 设置为 off，则可以创建该函数

postgres=# SHOW check_function_bodies;
 check_function_bodies 
-----------------------
 off
(1 row)

postgres=# \df
                       List of functions
 Schema | Name | Result data type | Argument data types | Type 
--------+------+------------------+---------------------+------
(0 rows)

postgres=# CREATE FUNCTION foo()
  RETURNS INT
  LANGUAGE SQL
AS 'SELECT * FROM bar()';
CREATE FUNCTION

在添加缺失的函数之前，该函数当然会以 ERROR 失败

postgres=# SELECT * FROM foo();
ERROR:  function bar() does not exist
LINE 1: SELECT * FROM bar()
                      ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
QUERY:  SELECT * FROM bar()
CONTEXT:  SQL function "foo" during inlining

• PostgreSQL 文档： check_function_bodies