We're descending a bit in database arcana (and not even the OPs database's), but what the hell:

Small tables don't use indexes. This 60-rows is a small table. I can't get Postgres to use an index for either 1/61 or 7/67 rows. (I even tried broadening the row with more columns, but no). Index-use only starts at a few hundred rows, for my example. A quick google search makes me think Oracle behaves the same. MySQL I'm not sufficiently interested in to go lookup; it's probably the same.

I don't see what clustered indexes have to do with the whole thing. Clustering reorganize the physical table data according to the index ordering. Obviously that can make things faster, but I rather suspect that clusteredness of an index has no bearing on plan choice.

In reply to Re^5: CGI Program To Delete Old Data From MySQL Table? by erix
in thread CGI Program To Delete Old Data From MySQL Table? by Milti

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