The different num of Dashborad's show and table

hi everyone,
I toke an dashborad for my table using kibana,I found the dashboard num different from is my sql as bellows:

SELECT DISTINCT(t.amount) FROM v_achievement_budget t WHERE t.amount BETWEEN 0 and 10;
the count is 200.
the dashborad inclund metrics which was using the unique count of amount,and the from 0 to 10 num is 204. why the dashborad more than table? anyone can explain the diffarent,very appreciate.

Best Regards,

Elasticsearch unique counts are an approximation, more details can be found at

You can configure the precision_threshold in kibana by adding a JSON input:

thanks for your quick response!