Hi everybody I am doing a modification to Dynamic programming algorithm in postgreSQL. I want to re-use a plan of one " joinrels" for another of the same level. For example,
if lev=5 , and let's say there are two combinations setA = {1,2,3,4,5} and set B={6,7,8,9,10}. I want to reuse the plan of {1.2,3,4,5} for {6,7,8,9,10}. But for this I need to create a relation that holds all the paths for {6,7,8,9,10}. I cannot just copy the relation holding join paths from setA. I need to create a new join relations using build_join_rel(). But I cannot do add_paths_to_joinrel() because that is the default path creation procedure. Instead I must be copying the paths of joinrel fo setA. So what I am doing now is : 1) Access the join relation for setA = {1,2,3,4,5}. 2) Pathlist = pathlist of joinrel(A). 3) foreach path "p" in pathlist of joinrel(A){ create new path "new_p" from path "p". left_child(new_p) = recursively copy from left child(p) right_child(new_p) = recursively copy from right child(p). } 4)But to do step 3 I need to know how to create pathkeys and I need to do the copy recursively, as I am trying to copy the path tree from top to bottom. Errors I get in doing this: ERROR: variable not found in subplan target lists Please give some insight. And please discuss with me on how to go about doing the path copy. Thanks Vamsi