Running mysql(5.5) /linux/ php/python Got a situation with a test env, where I'm dealing with a number of spawned processes, that might also spawn processes, so I have a "tree" where I'm looking to determine when the spawned processes have completed. To manage this cluster/tree of processes, I'm considering using a tree kind of DB representation:
The tables would be: ParentChildTBL ParentID, int ChildID int ItemStatusTBL Name, varchar ID, int Status int ItemStatusTBL.ID <-- ParentID/ChildID Tree Graph: top(1) | _________________________________________ | | | itemA(2) itemB(3) itemC(4) | ---------------------------------- | | | itemD(5) itemE(6) itemF(7) pseudo tbl representation ItemStatusTBL top, 1, 0 itemA, 2, 0 itemB, 3, 0 itemC, 4, 0 itemD, 5, 0 itemE, 6, 0 itemF, 7, 0 ParentChildTBL "",1 1,2 1,3 1,4 2,5 2,6 2,7 I've got a test app that spawns off child processes, where each process then updates the status of the corresponding given item upon completion. So the status in the itemStatusTBl will change from 0 to 1. I'm trying to determine how to efficiently be able to determine when the children of a given top/root node in the parentChildTBL are complete, ie, have the status set to '1'. (There could be multiple top level/root nodes, each with their own independent set of children) I could try to simply look at all the children each time I examine the tbl, but that might result in a lot of recursive function/processing in order to get to all the levels... I've looked at various articles, but not sure which is the best approach to this kind of issue. A complete run is determined by: when all children of the top level/root node != '0' Is this a self join,left join situation? A sample query/pointers would be helpful Thoughts/Thanks -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
