分析postgresql 数据库 update更新慢的原因及处理方法

select w1.pid as 等待进程,
w1.mode as 等待锁模式,
w2.usename as 等待用户,
w2.query as 等待会话,
b1.pid as 锁的进程,
b1.mode 锁的锁模式,
b2.usename as 锁的用户,
b2.query as 锁的会话,
b2.application_name 锁的应用,
b2.client_addr 锁的IP地址,
b2.query_start 锁的语句执行时间
from pg_locks w1
join pg_stat_activity w2 on w1.pid=w2.pid
join pg_locks b1 on w1.transactionid=b1.transactionid and w1.pid!=b1.pid
join pg_stat_activity b2 on b1.pid=b2.pid
where not w1.granted;

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE pid=’62560′

SELECT

C.relname 对象名称,
l.locktype 可锁对象的类型,
l.pid 进程id,
l.MODE 持有的锁模式,
l.GRANTED 是否已经对锁进行授权,
l.fastpath,
psa.datname 数据库名称,
psa.usesysid 用户id,
psa.usename 用户名称,
psa.application_name 应用程序名称,
psa.client_addr 连接的IP地址,
psa.client_port 连接使用的TCP端口号,
psa.backend_start 进程开始时间,
psa.xact_start 事务开始时间,
psa.query_start 事务执行此语句时间,
psa.state_change 事务状态改变时间,
psa.wait_event_type 等待事件类型,
psa.wait_event 等待事件,
psa.STATE 查询状态,

backend_xid 事务是否有写入操作,
backend_xmin 是否执事务快照,

psa.query 执行语句,
now( ) – query_start 持续时间

FROM

pg_locks l
INNER JOIN pg_stat_activity psa ON ( psa.pid = l.pid )
LEFT OUTER JOIN pg_class C ON ( l.relation = C.oid )
— where l.relation = ‘tb_base_apparatus’::regclass

where relkind =’r’
ORDER BY query_start asc

SELECT
c.relname 表名,
(current_setting(‘autovacuum_analyze_threshold’)::NUMERIC(12,4))+(current_setting(‘autovacuum_analyze_scale_factor’)::NUMERIC(12,4))*reltuples AS 自动分析阈值,
(current_setting(‘autovacuum_vacuum_threshold’)::NUMERIC(12,4))+(current_setting(‘autovacuum_vacuum_scale_factor’)::NUMERIC(12,4))*reltuples AS 自动清理阈值,
reltuples::DECIMAL(19,0) 活元组数,
n_dead_tup::DECIMAL(19,0) 死元组数
FROM
pg_class c

LEFT JOIN pg_stat_all_tables d

ON C.relname = d.relname
WHERE
c.relname LIKE’tb%’ AND reltuples > 0
AND n_dead_tup > (current_setting(‘autovacuum_analyze_threshold’)::NUMERIC(12,4))+(current_setting(‘autovacuum_analyze_scale_factor’)::NUMERIC(12,4))*reltuples;

VACUUM FULL VERBOSE 表名;
VACUUM FULL VERBOSE ANALYZE 表名;