On Sat, 07 Sep 2002 10:21:21 -0700
Joe Conway <mail@joeconway.com> wrote:
> I just sent in a patch using the ancestor check method. It turned out
> that the performance hit was pretty small on a moderate sized tree.
>
> My test case was a 220000 record bill-of-material table. The tree built
> was 9 levels deep with about 3800 nodes. The performance hit was only
> about 1%.
The previous patch fixed an infinite recursion bug in
contrib/tablefunc/tablefunc.c:connectby. But, other unmanageable error
seems to occur even if a table has commonplace tree data(see below).
I would think the patch, ancestor check, should be
if (strstr(branch_delim || branchstr->data || branch_delim, branch_delim || current_key ||
branch_delim))
This is my image, not a real code. However, if branchstr->data includes
branch_delim, my image will not be perfect.
-- test connectby with int based hierarchy
DROP TABLE connectby_tree;
CREATE TABLE connectby_tree(keyid int, parent_keyid int);
INSERT INTO connectby_tree VALUES(11,NULL);
INSERT INTO connectby_tree VALUES(10,11);
INSERT INTO connectby_tree VALUES(111,11);
INSERT INTO connectby_tree VALUES(1,111);
SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', '11', 0, '-') AS t(keyid int, parent_keyid int,
levelint, branch text)
ERROR: infinite recursion detected
Regards,
Masaru Sugawara
