Change Assert(Ptp.t_data->t_xmax == tp.t_data->t_xmin) to :

/*
 * Read above about cases when !ItemIdIsUsed(Citemid)
 * (child item is removed)... Due to the fact that
 * at the moment we don't remove unuseful part of
 * update-chain, it's possible to get too old
 * parent row here. Like as in the case which
 * caused this problem, we stop shrinking here.
 * I could try to find real parent row but want
 * not to do it because of real solution will
 * be implemented anyway, latter, and we are too
 * close to 6.5 release.        - vadim 06/11/99
 */
if (Ptp.t_data->t_xmax != tp.t_data->t_xmin)
...

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index bfc9094b4827a661b6a36ecc5c163d8f616be1f9..ef8a1bffd7d4934ad5868b086bbbc0881cb7688e 100644 (file)
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.108 1999/06/10 14:17:07 vadim Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.109 1999/06/11 09:35:08 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1353,8 +1353,33 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                        Ptp.t_data = (HeapTupleHeader) PageGetItem(Ppage, Pitemid);
                        Assert(ItemPointerEquals(&(vtld.new_tid),
                                                &(Ptp.t_data->t_ctid)));
-                       Assert(Ptp.t_data->t_xmax == tp.t_data->t_xmin);
-
+                       /*
+                        * Read above about cases when !ItemIdIsUsed(Citemid)
+                        * (child item is removed)... Due to the fact that
+                        * at the moment we don't remove unuseful part of 
+                        * update-chain, it's possible to get too old
+                        * parent row here. Like as in the case which 
+                        * caused this problem, we stop shrinking here.
+                        * I could try to find real parent row but want
+                        * not to do it because of real solution will
+                        * be implemented anyway, latter, and we are too
+                        * close to 6.5 release.        - vadim 06/11/99
+                        */
+                       if (Ptp.t_data->t_xmax != tp.t_data->t_xmin)
+                       {
+                           if (freeCbuf)
+                               ReleaseBuffer(Cbuf);
+                           freeCbuf = false;
+                           ReleaseBuffer(Pbuf);
+                           for (i = 0; i < num_vtmove; i++)
+                           {
+                               Assert(vtmove[i].vpd->vpd_offsets_used > 0);
+                               (vtmove[i].vpd->vpd_offsets_used)--;
+                           }
+                           num_vtmove = 0;
+                           elog(NOTICE, "Too old parent tuple found - can't continue vc_rpfheap");
+                           break;
+                       }
 #ifdef NOT_USED            /* I'm not sure that this will wotk properly... */
                        /*
                         * If this tuple is updated version of row and it
@@ -1382,6 +1407,8 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                        freeCbuf = true;
                        break;
                    }
+                   if (num_vtmove == 0)
+                       break;
                }
                if (freeCbuf)
                    ReleaseBuffer(Cbuf);