I don't really understand this. What do you mean by 'index'? In rdbms, index can only contain data that can be trivially derived from tables. Everything needs to work without index as well.
On Dec 30, 2011 4:42 PM, "Seth Johnson" <[email protected]> wrote: > > On Fri, Dec 30, 2011 at 9:13 AM, Ville M. Vainio <[email protected]> wrote: > > On Fri, Dec 30, 2011 at 3:25 PM, Seth Johnson <[email protected]> wrote: > > > >> One can use two indexes instead of having an edges entity: > >> > >> To find all children of node N, seek N in an index on the parent key > >> field. Skip through until it doesn't match. > > > > This doesn't work if N is cloned somewhere, i.e. N has several parents. > > Node key - Parent key > A - N > B - N > C - N > D - X > E - X > N - D > N - E > > X - D - N - A > \ B > \ C > \ E - N - A > \ B > \ C > > To find all children of node N, seek N in an index on the parent key > field. Skip through until it doesn't match. > > Node key - Parent key > A - N > B - N > C - N > > > To find all parents of node N, seek N in an index on the node key > field. Skip through (reading the parent key field) until it doesn't > match. > > Node key - Parent key > N - D > N - E > > > Seems to work . . . > > > Seth > > -- > You received this message because you are subscribed to the Google Groups "leo-editor" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to [email protected]. > For more options, visit this group at http://groups.google.com/group/leo-editor?hl=en. > -- You received this message because you are subscribed to the Google Groups "leo-editor" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/leo-editor?hl=en.
