当我再输入〜15000个参数时，为什么PostgreSQL使用100％cpu

Question

这是我的查询：select * from dbname where user_name = any(cast(? as text[]))

我的conf文件：

max_connections = 100
shared_buffers = 1GB
effective_cache_size = 3GB
maintenance_work_mem = 256MB
checkpoint_completion_target = 0.7
wal_buffers = 16MB
default_statistics_target = 100
random_page_cost = 4
effective_io_concurrency = 2
work_mem = 300MB
min_wal_size = 512MB
max_wal_size = 2GB

当我放少于15000时，一切正常。

Postgresq 9.5。

Answer 1

不确定Hibernate是否可行，但是您可以尝试加入连接：

select t.* 
from tablename t 
   join unnest(cast(? as text[])) as x(name) on t.user_name = x.name