| EAV | attr_name / attr_value 行式存储 |
|---|---|
| 代价 | join 多、类型弱、校验难 |
| 替代 | 固定列 + 标签表 |
EAV 查询之痛
EAV 查询之痛
-- 每次取两个属性都要自连接
SELECT a.entity_id
FROM dim_eav a JOIN dim_eav b ON a.entity_id = b.entity_id
WHERE a.attr = 'color' AND a.val = 'red'
AND b.attr = 'size' AND b.val = 'L';属性稳定且经常组合查询时，应直接建列并建索引。