postgresql - pg_stat_statements 启用，但表不存在

Question

我已经启动并运行了 postgresql-9.4，并且最近在官方的帮助下启用了 pg_stat_statements 模块 documentation .

但我在使用时遇到以下错误:

postgres=# SELECT * FROM pg_stat_statements;
ERROR:  relation "pg_stat_statements" does not exist
LINE 1: SELECT * FROM pg_stat_statements;


postgres=# SELECT pg_stat_statements_reset();
ERROR:  function pg_stat_statements_reset() does not exist
LINE 1: SELECT pg_stat_statements_reset();

我使用 postgres 用户登录到 psql。我还检查了可用的扩展列表:

postgres=# SELECT * FROM pg_available_extensions WHERE name = 'pg_stat_statements'
;
        name        | default_version | installed_version |                          comment                          
--------------------+-----------------+-------------------+-----------------------------------------------------------
 pg_stat_statements | 1.2             |                   | track execution statistics of all SQL statements executed
(1 row)

下面是扩展版本查询的结果:

postgres=# SELECT * FROM pg_available_extension_versions WHERE name = 'pg_stat_statements';
        name        | version | installed | superuser | relocatable | schema | requires |                          comment                          
--------------------+---------+-----------+-----------+-------------+--------+----------+-----------------------------------------------------------
 pg_stat_statements | 1.2     | f         | t         | t           |        |          | track execution statistics of all SQL statements executed
(1 row)

我们将不胜感激。

Answer 1

未安装扩展:

SELECT * 
FROM pg_available_extensions 
WHERE 
    name = 'pg_stat_statements' and 
    installed_version is not null;

如果表为空，创建扩展:

CREATE EXTENSION pg_stat_statements;