But before CTEs this sort of thing had regular use with recursive tree structures, in caching hierarchies. You'd make use of whatever SQL options you had to concatenate a group of IDs into a comma-separated string.
e.g. all the parent nodes of a given node in the hierarchy, and even (selectively) for caching all the descendent node IDs of enclosures. Though there are better ways to do this for trees that could be truly arbitrarily deep.
But before CTEs this sort of thing had regular use with recursive tree structures, in caching hierarchies. You'd make use of whatever SQL options you had to concatenate a group of IDs into a comma-separated string.
e.g. all the parent nodes of a given node in the hierarchy, and even (selectively) for caching all the descendent node IDs of enclosures. Though there are better ways to do this for trees that could be truly arbitrarily deep.