常见 DB 基础细节
Mongo
cmds
db.happygame_sdk.test.getIndexes(); db.happygame_sdk.test.explain("executionStats").find({'playerid':'ad3e5eb8-a03c-5011-8f2d-ce32c2a7ab31'});
Mysql
了解数据库的一些基本理论知识:
数据的存储格式 (堆组织表 vs 聚簇索引表)
并发控制协议 (MVCC vs Lock-Based CC)
Two-Phase Locking
数据库的隔离级别定义 (Isolation Level)
了解SQL本身的执行计划
主键扫描 vs 唯一键扫描 vs 范围扫描 vs 全表扫描
了解数据库本身的一些实现细节
过滤条件提取
Index Key/Index Filter/Table Filter
Index Condition Pushdown
Semi-Consistent Read
查看数据库空间占用:
SELECT CONCAT(table_schema,'.',table_name) AS 'Table Name', CONCAT(ROUND(table_rows/1000000,4),'M') AS 'Number of Rows', CONCAT(ROUND(data_length/(1024*1024*1024),4),'G') AS 'Data Size', CONCAT(ROUND(index_length/(1024*1024*1024),4),'G') AS 'Index Size', CONCAT(ROUND((data_length+index_length)/(1024*1024*1024),4),'G') AS'Total' FROM information_schema.TABLES WHERE table_schema LIKE 'weixin_game' order by Total desc;
锁
乐观锁、悲观锁(读锁、互斥锁)
mysql 死锁分析
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