[BritSteve]

What is the ratio of rows that satisfy the condition? I mean how many of the 100,000 rows have a fieldid of 4 and are not null. Is there a primary key, like ID that is numeric?

I agree that the SQL is getting the relevant rows, adding the rand and then sorting them, probably using a temp table.

There are other ways you can try, but it will involve some PHP coding.

Steve