Does a SELECT happen all at once, or progressively

Posted by AmbroseChapel on Stack Overflow See other posts from Stack Overflow or by AmbroseChapel
Published on 2010-05-28T00:08:06Z Indexed on 2010/05/28 0:11 UTC
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mysql

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select

I have a process which finds a list of files to be deleted using a SELECT wheredelete= 'Y'.

I set this process running the other day but it takes a while because it actually does the file deletions too.

And in the middle of its long operation, I was using the application and deleted one more file.

At this point I realised I didn't know if that file would be deleted, because I didn't know if the SELECT would have found all the files at the start, or if it was finding them progressively and would get to my newly-deleted file eventually.

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