MYSQL查询执行时间

Question

我有一个问题问你。 我的数据库有250.000条记录，其中2个文本字段最多包含300个单词。 我想选择所有符合某些条件的数据，然后将其放在另一个表中。 我想删除这些不符合我的条件的录音：

DELETE FROM `cables` WHERE 
`data` NOT LIKE "%BRV%" AND
`data` NOT LIKE "%Venezuela%" AND
`data` NOT LIKE "%Caracas%" AND
`data` NOT LIKE "%Hugo Chavez%" AND
`tags` NOT LIKE "%BRV%" AND
`tags` NOT LIKE "%Venezuela%" AND
`tags` NOT LIKE "%Caracas%" AND
`tags` NOT LIKE "%Hugo Chavez%" AND
`header` NOT LIKE "%BRV%" AND
`header` NOT LIKE "%Venezuela%" AND
`header` NOT LIKE "%Caracas%" AND
`header` NOT LIKE "%Hugo Chavez%" AND
`subject` NOT LIKE "%BRV%" AND
`subject` NOT LIKE "%Venezuela%" AND
`subject` NOT LIKE "%Caracas%" AND
`subject` NOT LIKE "%Hugo Chavez%" AND
`tmp` NOT LIKE "%BRV%" AND
`tmp` NOT LIKE "%Venezuela%" AND
`tmp` NOT LIKE "%Caracas%" AND
`tmp` NOT LIKE "%Hugo Chavez%" AND
`identifier` NOT LIKE "%BRV%" AND
`identifier` NOT LIKE "%Venezuela%" AND
`identifier` NOT LIKE "%Caracas%" AND
`identifier` NOT LIKE "%Hugo Chavez%"

如果每一行至少包含这些单词中的任何一个，则可以。 事实是，自执行以来，我已经有3个小时了，什么也没发生。 我已经停止了该过程，但没有任何反应。 最终结果应该有大约14000张录音，我该怎么办？ 谢谢！！！！

Answer 1

什么都没发生，因为您停止了它。 因此， commit; 尚未完成。

您应该拆分查询以缩短执行时间。

NOT LIKE %%非常非常昂贵！！！ （索引，如果有一些未使用...）

Answer 2

尝试REGEXP ，在这里可能会更好。

DELETE FROM `cables` WHERE
  `data` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez' AND
  `tags` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez' AND
  `header` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez' AND
  `subject` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez' AND
  `tmp` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez' AND
  `identifier` NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez'

也可以串联使用（Karolis的建议）

DELETE FROM `cables` WHERE
   CONCAT( `data`, `tags`, `header`, `subject`, `tmp`, `identifier` )
   NOT REGEXP 'BRV|Venezuela|Caracas|Hugo Chavez'

Answer 3

问题在于， LIKE %text%将不会使用全文索引。 因此，包含250.000个条目和很多LIKE %%标准的大型表将花费很长时间。

您确定需要前导的“％...”吗？ 否则，您可以尝试使用布尔搜索修饰符 。

Answer 4

为什么不反转条件以选择匹配的记录，而不是删除不匹配的记录？ 然后将它们插入另一个表？ 这可能会更快一些，因为即使过度使用非常规条件也要3个小时，对于250'000行来说太长了。

INSER INTO `selected_cables`
SELECT * FROM `cables`
WHERE NOT ( 
`data` NOT LIKE "%BRV%" AND
`data` NOT LIKE "%Venezuela%" AND
`data` NOT LIKE "%Caracas%" AND
`data` NOT LIKE "%Hugo Chavez%" AND
`tags` NOT LIKE "%BRV%" AND
`tags` NOT LIKE "%Venezuela%" AND
`tags` NOT LIKE "%Caracas%" AND
`tags` NOT LIKE "%Hugo Chavez%" AND
`header` NOT LIKE "%BRV%" AND
`header` NOT LIKE "%Venezuela%" AND
`header` NOT LIKE "%Caracas%" AND
`header` NOT LIKE "%Hugo Chavez%" AND
`subject` NOT LIKE "%BRV%" AND
`subject` NOT LIKE "%Venezuela%" AND
`subject` NOT LIKE "%Caracas%" AND
`subject` NOT LIKE "%Hugo Chavez%" AND
`tmp` NOT LIKE "%BRV%" AND
`tmp` NOT LIKE "%Venezuela%" AND
`tmp` NOT LIKE "%Caracas%" AND
`tmp` NOT LIKE "%Hugo Chavez%" AND
`identifier` NOT LIKE "%BRV%" AND
`identifier` NOT LIKE "%Venezuela%" AND
`identifier` NOT LIKE "%Caracas%" AND
`identifier` NOT LIKE "%Hugo Chavez%")