单选题The ST_INFO master table has millions of rows that are updated very rarely. It has a STATE_CODE column that contains the value for 25 states. The table is frequently queried on the STATE_CODE column. Which type of index would you suggest to improve the query performance？（）AB-treeBbitmapCreverse keyDfunction based
单选题
The ST_INFO master table has millions of rows that are updated very rarely. It has a STATE_CODE column that contains the value for 25 states. The table is frequently queried on the STATE_CODE column. Which type of index would you suggest to improve the query performance？（）
A
B-tree
B
bitmap
C
reverse key
D
function based
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