Question

I have a question for you. I have this database with 250.000 recordings, with 2 text fields each containing up to 300 words. And I want do select all the data that meets some criteria and put it in another table. I thought to delete those recording that are not satisfying my condition with this wuery:

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%"

Each row is OK if it containt at least one time any of those words. The thing is that I already have 3 hours since it is being in execution, and nothing hapened. I’ve stopped the proccess and nothing happened. The final resuls should have somewhere around 14000 recordings, What can I do? Thank you!!!!

Answer 1

The problem is that LIKE %text% will not make use of a fulltext index. So a big table with 250.000 entries and a lot of LIKE %% criterias will take an awful long time.

Are you sure you need the leading ‘%…’? Otherwise you can try to use Boolean search modifier.