How to quickly SELECT 3 random records from a 30k MySQL table with a where filter by a single query?

Question

Well, this is a very old question never gotten real solution. We want 3 random rows from a table with about 30k records. The table is not so big in point of view MySQL, but

Answer 1

What about creating another table containing only items with image ? This table will be much lighter as it will contain only one-third of the items the original table has !

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|ID     | Item ID (on the original table)|
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|0      | 0                              |
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|1      | 123                            |
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            .
            .
            .
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|10 000 | 30 000                         |
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You can then generate three random IDs in the PHP part of the code and just fetch'em the from the database.