the same query takes about 200 ms in Oracle and MSSQL. Which leaves me wondering, what is exactly going on here. When I add aLIMIT 100, it reduces the query performance to 100 ms
Update: I've reduced the problem below. See the difference between IN (4747) and IN (SELECT 4747). Slow: >> explain analyze SELECT * FROM ( SELECT player_id, color FROM player_data GROUP BY player_id, color ORDER BY MAX(active_time) DESC ) S WHERE player_id IN (SELECT 4747); Ha...
I've inherited an Django/postgres app from another developer and I'm finding many of the queries are very slow. I've spent a lot of time correctly organising/normalising the data which was not done before which has helped a lot but some queries can still take minutes. In particular we ...
11 Slow fulltext search due to wildly inaccurate row estimates 5 Why does PostgreSQL perform a seq scan when comparing a numeric value with a bigint column? 23 How to make DISTINCT ON faster in PostgreSQL? 0 Help Troubleshooting Full-text Search Function Performance Hot Network Questions ...
The benefits of more recent major versions include new features, improved performance, and an ability to define a higher security posture. In this post, we cover the Amazon Aurora PostgreSQL-Compatible Edition and Amazon RDS for PostgreSQL end-of-life (EOL) timeline, featu...
UPDATEtest_tableSETdata=updatedWHEREid=num; END; $$LANGUAGEplpgsql; --使用pgTap测试函数性能 SELECTplan(1); SELECTdiag(Startingperformancetestformy_function); SELECTtiming_start(); SELECTmy_function(50000); SELECTtiming_stop(); SELECT*FROMfinish(); ...
update user set user.Host='%' where user.User='root'; 刷新权限: flush privileges; 12、设置mysql开机自启动。 13、设置mysql开机自启动 chkconfig --add mysqld # 检查mysqld服务是否已经生效 chkconfig --list mysqld 14、可以完/etc下添加my.cnf配置文件,mysql开启时会默认去/etc/my.cnf 加载该配置...
- Likewise I have worked in postgres since its version 8.1 to 9.6.6 and a positive change has been noticed and performance improvements, but I insist on the point at which the databases should be fine designed.CONS - Many people declare it as slow in insertions and updates compared to ...
In this blog post, we cover PostgreSQL performance tuning and establish some basic guidelines for setting database parameters to enhance PostgreSQL performance.
1. 为了提高更新速度,使用了FASTER UPDATE技术,当BUFFER很大时(可自己设置),查询速度可能会较慢。所以权衡插入和查询,建议设置合理的BUFFER大小。 2. 仅支持bitmap查询,也就是说取到所有的行号之后,排序,然后再去检索,好处显然是可以减少随机的HEAP PAGE扫描,但是坏处是,当涉及的行非常多(比如每行都包含了某个元...