利用pg_stat_statements排查PostgreSQL中的慢SQL

1. 编辑postgresql.conf
   • shared_preload_libraries = 'pg_stat_statements'
   • track_activity_query_size = 16384
2. 启用扩展create extension pg_stat_statements
3. 查找慢SQL

   select round((100 * total_time / sum(total_time) over ())::numeric, 2) percent,
          round(total_time::numeric, 2) as                                total,
          calls,
          round(mean_time::numeric, 2)  as                                mean,
          query
   from pg_stat_statements
   order by total_time desc;