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Asked: 2026-06-01T20:27:34+00:00

I got two tables (one with 33k rows and another with 7k rows). I

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I got two tables (one with 33k rows and another with 7k rows). I want to compare the two tables and delete the rows in which the two id’s dont match. But when i send off the query, it freezes phpmyadmin. Could the tables be too big?

SELECT * FROM likes LEFT OUTER JOIN uploads on likes.upload_id = uploads.upload_id WHERE uploads.upload_id IS NULL

I know databases are meant to handle millions of data, so i’m not sure where the error lies.

Best regards,
Mathias

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1 Answer

  1. Editorial Team

    I would do an explain so you can see what mysql does. This would give a good indication on what how many rows are used.

    EXPLAIN SELECT * FROM likes LEFT OUTER JOIN uploads on likes.upload_id = uploads.upload_id WHERE uploads.upload_id IS NULL

    you could also use another browser or another session to use show processlist to see how the query is executed.

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