在排序V2.1 Sphinx时发现总计数错过匹配

Question

当我对某个unixtimestamp日期字段进行排序时，total_found计数显示不同的结果。这是我的查询

SELECT * FROM CA_SAC_persons,CA_KC_persons,CA_SFC_persons,CA_SJ_persons
WHERE MATCH('@fullname("^John$" | "^Joseph$" | "^Jose$" | "^Josh$" | "^Robs$")') 
ORDER BY filing_date_ts DESC LIMIT 0,1;SHOW META; 

Result :
+---------------+-------------+
| Variable_name | Value       |
+---------------+-------------+
| total         | 1000        |
| total_found   | 4813        |
| time          | 0.019       |
| docs[9]       | 4603        | 
| hits[9]       | 5312        |
+---------------+-------------+

SELECT * FROM CA_SAC_persons,CA_KC_persons,CA_SFC_persons,CA_SJ_persons
WHERE MATCH('@fullname("^John$" | "^Joseph$" | "^Jose$" | "^Josh$" | "^Robs$")') 
ORDER BY filing_date_ts ASC LIMIT 0,1;SHOW META; 

Result :
+---------------+-------------+
| Variable_name | Value       |
+---------------+-------------+
| total         | 1000        |
| total_found   | 4812        |
| time          | 0.019       |
| docs[9]       | 4603        | 
| hits[9]       | 5312        |
+---------------+-------------+

为什么total_found在第二个查询中显示少于1个记录？