PostgreSQL监控脚本

往往我们对着一堆系统状态视图不知所措，这里我整理一些学习到的脚本：

后续慢慢补充～


－－20170913－－
这部分参考了http://blog.postgresql-consulting.com

pg_stat_replication：

SELECT
  client_addr AS client, usename AS user, application_name AS name,
  state, sync_state AS mode,
  (pg_xlog_location_diff(pg_current_xlog_location(),sent_location) / 1024)::bigint as pending,
  (pg_xlog_location_diff(sent_location,write_location) / 1024)::bigint as write,
  (pg_xlog_location_diff(write_location,flush_location) / 1024)::bigint as flush,
  (pg_xlog_location_diff(flush_location,replay_location) / 1024)::bigint as replay,
  (pg_xlog_location_diff(pg_current_xlog_location(),replay_location))::bigint / 1024 as total_lag
FROM pg_stat_replication;

 

pg_stat_all_tables：

 

SELECT
    schemaname, relname,
    seq_scan, seq_tup_read,
    seq_tup_read / seq_scan as avg_seq_tup_read
FROM pg_stat_all_tables
WHERE seq_scan > 0
ORDER BY 5 DESC LIMIT 5;

pg_stat_database：

查看数据库块命中率：
SELECT
  datname, 100 * blks_hit / (blks_hit + blks_read) as cache_hit_ratio
FROM pg_stat_database WHERE (blks_hit + blks_read) > 0;

or：

SELECT 
  round(100 * sum(blks_hit) / sum(blks_hit + blks_read), 3) as cache_hit_ratio
FROM pg_stat_database;

SELECT 
  datname, 100 * xact_commit / (xact_commit + xact_rollback) as commit_ratio
FROM pg_stat_database WHERE (xact_commit + xact_rollback) > 0;

pg_stat_bgwriter：

pg_stat_bgwrite：

 －－20170913－－