我有一张约有5000万条记录的表格.
表结构如下所示,callerid和call_start字段都被编入索引.
id - callerid - call_start
我想选择他们的call_start大于'2013-12-22'的所有记录,并且在整个表格中'callerid'在'2013-12-22'之前没有重复.
我使用过这样的东西:
SELECT DISTINCT
ca.`callerid`
FROM
call_archives AS ca
WHERE ca.`call_start` >= '2013-12-22'
AND ca.`callerid` NOT IN
(SELECT DISTINCT
ca.`callerid`
FROM
call_archives AS ca
WHERE ca.`call_start` < '2013-12-21')
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但这非常慢,任何建议都非常感激.