www.sitepoint.com/hierarchical-data-database/ ... This old post from another site] describes another way to do it – modified pre-order traversal trees (MPTTs). Strangely, I did not immediately identify suport for them in CPAN but they surely must be in there somewhere.

In reply to Re: [OT] MySQL recalibrating a sort-index by Anonymous Monk
in thread [OT] MySQL recalibrating a sort-index by LanX

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