目录1 案发现场2 第一次优化3 第二次优化exists和not exists常用示例说明1.查询a表在b表中存在数据2.查询a表在b表中不存在数据3.查询时间最新记录4.exists替代distinct剔除重复数据总结最近我在公司优化了一些慢查询
Looking to understand what my EXPLAIN results mean here, and to optimize this query and my tables as best as I can.
I hava a table items and a table item_attributes. For simplicity let\'s say my table item has a column id and a column name.
I use MySQL server version 5.5.14 and now I am trying this simple SQL query with Explain command: EXPLAIN SELECT id, name, thumb FROM `twitter_profiles` LIMIT 10;
Stress testing a site & everything is breaking, obviously. Today\'s problem: WSOD on several pages. After a few hours I have narrowed the problem on one page down to this query (I hope): It used
I\'m planning on creating a view using this SQL SELECT, but the explain for it shows it\'s using temporary and using filesort. I can\'t figure out what indices I need in order to fix this problem.
I have a table from a legacy system which does not have a primary key. It records transactional data for issuing materials in a factory.
I havea query that is performing poorly.Server version: 5.1.37-1ubuntu5.1 (Ubuntu) SELECT * FROM `influencers` WHERE (`influencers`.`twitter_id` = 86861293)LIMIT 1
I am far from a SQL guru and I am trying to execute: SELECT `apps`.* FROM `apps` INNER JOIN `similars`
I am trying to optimize the following modified MySQL query from OsCommerce: select distinct p.products_id, pd.products_name, m.manufacturers_name, s.specials_new_products_price from products p
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