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);