pg数据库优化
1.定期进行手动postgresql vacuum操作
https://www.cnblogs.com/hicuiyang/p/10436733.html
https://www.cnblogs.com/pengai/p/8073218.html
https://blog.csdn.net/pg_hgdb/article/details/79490875
https://www.cnblogs.com/xibuhaohao/p/11132771.html
https://www.runoob.com/sqlite/sqlite-vacuum.html
http://blog.itpub.net/30088583/viewspace-1592066/
http://www.postgres.cn/docs/9.4/sql-vacuum.html
2.truncate命令https://blog.csdn.net/weixin_34122810/article/details/86363328