达梦数据库指定索引

达梦数据库指定索引

语法

表名 + INDEX + 索引名
或
/*+ INDEX (表名[,] 索引名) {INDEX (表名[,] 索引名)} */（表明可以使用别名）

指定查询优化器使用的索引——Hint提示

使用

达梦数据库指定索引
方式一：

select PREDICTION_TYPE,PREDICTION_TIME , sum(PREDICTION_VALUE) PREDICTION_VALUE
from PREDICTION_POWER_STATISTICS INDEX INDEX33556034
where PREDICTION_TYPE = 1
and PREDICTION_TIME between '2022-11-01 00:00:00' and '2022-11-30 00:00:00'
and id in (2,3,4,5,6,7,8,9,10)
group by  PREDICTION_TYPE, PREDICTION_TIME;
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方式二：

select /*+ INDEX(PREDICTION_POWER_STATISTICS INDEX33556034)*/ PREDICTION_TYPE,PREDICTION_TIME , sum(PREDICTION_VALUE) PREDICTION_VALUE
from PREDICTION_POWER_STATISTICS 
where PREDICTION_TYPE = 1
and PREDICTION_TIME between '2022-11-01 00:00:00' and '2022-11-30 00:00:00'
and id in (2,3,4,5,6,7,8,9,10)
group by  PREDICTION_TYPE, PREDICTION_TIME;
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查询表索引

查询表索引名称

select table_name,index_name from dba_indexes where table_name=表名

参考文章

DM7 达梦数据库 查询优化 – HINT 提示