Re: output branches before infinite recursion using connectby()?

Zhenchang Xing wrote:
> is it possible to output the branches before the detection of infinite
> recursion when using connectby()?

It is possible if you patch the distributed source ;-)

Not heavily tested, but the attached patch against 7.4 seems to do the
trick for me. I'm not really sure I'd want this in the distribution
though -- anyone else with opinions?

Joe
Index: tablefunc.c
===================================================================
RCS file: /cvsroot/pgsql-server/contrib/tablefunc/tablefunc.c,v
retrieving revision 1.25.2.2
diff -c -r1.25.2.2 tablefunc.c
*** tablefunc.c    11 Aug 2004 01:02:07 -0000    1.25.2.2
--- tablefunc.c    30 Sep 2004 22:51:42 -0000
***************
*** 1416,1421 ****
--- 1416,1423 ----

          for (i = 0; i < proc; i++)
          {
+             bool    recursion_detected = false;
+
              /* initialize branch for this pass */
              appendStringInfo(branchstr, "%s", branch);
              appendStringInfo(chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim);
***************
*** 1433,1439 ****

              /* check to see if this key is also an ancestor */
              if (strstr(chk_branchstr->data, chk_current_key->data))
!                 elog(ERROR, "infinite recursion detected");

              /* OK, extend the branch */
              appendStringInfo(branchstr, "%s%s", branch_delim, current_key);
--- 1435,1444 ----

              /* check to see if this key is also an ancestor */
              if (strstr(chk_branchstr->data, chk_current_key->data))
!             {
!                 elog(NOTICE, "infinite recursion detected");
!                 recursion_detected = true;
!             }

              /* OK, extend the branch */
              appendStringInfo(branchstr, "%s%s", branch_delim, current_key);
***************
*** 1471,1477 ****
              heap_freetuple(tuple);

              /* recurse using current_key_parent as the new start_with */
!             tupstore = build_tuplestore_recursively(key_fld,
                                                      parent_key_fld,
                                                      relname,
                                                      orderby_fld,
--- 1476,1483 ----
              heap_freetuple(tuple);

              /* recurse using current_key_parent as the new start_with */
!             if (!recursion_detected)
!                 tupstore = build_tuplestore_recursively(key_fld,
                                                      parent_key_fld,
                                                      relname,
                                                      orderby_fld,