前提准备
重置监听计数器
进入 psql 终端，输入如下命令：
create extension pg_stat_statements; -- 这个命令只需要执行一次，不需要重复启用 select pg_stat_reset(); select pg_stat_statements_reset();点击复制复制失败已复制
按照实际情况开始等待一段时间，之后开始查询监听结果
select * from pg_stat_statements order by max_exec_time desc limit 5; -- 查询执行所需时间最慢的5条SQL语句点击复制复制失败已复制
pg_stat_statements表的结构如下：
| 列名 | 类型 | 描述 |
| userid | oid（references pg_authid.oid） | 执行语句的用户OID |
| dbid | oid (references pg_database.oid) | 执行语句的数据库OID |
| queryid | bigint | 内部hash码，从执行语句的语法树上计算得到 |
| query | text | 执行的SQL语句 |
| plans | bigint | Number of times the statement was planned (if pg_stat_statements.track_planning is enabled, otherwise zero) |
| total_plan_time | double precision | Total time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero) |
| min_plan_time | double precision | Minimum time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero) |
| max_plan_time | double precision | Maximum time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero) |
| mean_plan_time | double precision | Mean time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero) |
表格未完待续。。。
