Added: dynamic re-moving page from list of pages usable for shrinking

if its free-space < min_tuple_len.

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 4d2c96094a6cc8d9b138607555b8713eea01fe31..66fc0a19b224e79c47fe2a471d27e337bc5aa47a 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 1.10 1996/11/28 04:37:38 vadim Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.11 1996/11/29 10:27:59 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -462,6 +462,7 @@ _vc_scanheap (VRelList curvrl, Relation onerel,
 {
     int nblocks, blkno;
     ItemId itemid;
+    ItemPointer itemptr;
     HeapTuple htup;
     Buffer buf;
     Page page, tempPage = NULL;
@@ -611,6 +612,33 @@ DELETE_TRANSACTION_ID_VALID %d, TUPGONE %d.",
            tupgone);
        }
        
+       /*
+        * It's possibly! But from where it comes ?
+        * And should we fix it ?  - vadim 11/28/96
+        */
+       itemptr = &(htup->t_ctid);
+       if ( !ItemPointerIsValid (itemptr) || 
+               BlockIdGetBlockNumber(&(itemptr->ip_blkid)) != blkno )
+       {
+           elog (NOTICE, "ITEM POINTER IS INVALID: %u/%u FOR %u/%u. TUPGONE %d.", 
+               BlockIdGetBlockNumber(&(itemptr->ip_blkid)), 
+               itemptr->ip_posid, blkno, offnum, tupgone);
+       }
+
+       /*
+        * Other checks...
+        */
+       if ( htup->t_len != itemid->lp_len )
+       {
+           elog (NOTICE, "PAGEHEADER' LEN %u IS NOT THE SAME AS HTUP' %u FOR %u/%u.TUPGONE %d.", 
+               itemid->lp_len, htup->t_len, blkno, offnum, tupgone);
+       }
+       if ( !OidIsValid(htup->t_oid) )
+       {
+           elog (NOTICE, "OID IS INVALID FOR %u/%u.TUPGONE %d.", 
+               blkno, offnum, tupgone);
+       }
+       
        if (tupgone) {
        ItemId lpp;
                                                     
@@ -676,6 +704,10 @@ DELETE_TRANSACTION_ID_VALID %d, TUPGONE %d.",
     /* save stats in the rel list for use later */
     curvrl->vrl_ntups = ntups;
     curvrl->vrl_npages = nblocks;
+    if ( ntups == 0 )
+       min_tlen = max_tlen = 0;
+    curvrl->vrl_min_tlen = min_tlen;
+    curvrl->vrl_max_tlen = max_tlen;
     
     Vvpl->vpl_nemend = nemend;
     Fvpl->vpl_nemend = nemend;
@@ -746,6 +778,7 @@ _vc_rpfheap (VRelList curvrl, Relation onerel,
     InsertIndexResult iresult;
     VPageListData Nvpl;
     VPageDescr ToVpd = NULL, Fvplast, Vvplast, vpc, *vpp;
+    int ToVpI = 0;
     IndDesc *Idesc, *idcur;
     int Fblklast, Vblklast, i;
     Size tlen;
@@ -872,8 +905,31 @@ _vc_rpfheap (VRelList curvrl, Relation onerel,
        ! _vc_enough_space (ToVpd, tlen) )
        {
        if ( ToBuf != InvalidBuffer )
+       {
            WriteBuffer(ToBuf);
-       ToBuf = InvalidBuffer;
+           ToBuf = InvalidBuffer;
+           /*
+            * If no one tuple can't be added to this page -
+            * remove page from Fvpl. - vadim 11/27/96
+            */ 
+           if ( !_vc_enough_space (ToVpd, curvrl->vrl_min_tlen) )
+           {
+               if ( ToVpd != Fvplast )
+               {
+                   Assert ( Fnpages > ToVpI + 1 );
+                   memmove (Fvpl->vpl_pgdesc + ToVpI, 
+                       Fvpl->vpl_pgdesc + ToVpI + 1, 
+                       sizeof (VPageDescr*) * (Fnpages - ToVpI - 1));
+               }
+               Assert ( Fnpages >= 1 );
+               Fnpages--;
+               if ( Fnpages == 0 )
+                   break;
+           /* get prev reapped page from Fvpl */
+           Fvplast = Fvpl->vpl_pgdesc[Fnpages - 1];
+           Fblklast = Fvplast->vpd_blkno;
+           }
+       }
        for (i=0; i < Fnpages; i++)
        {
            if ( _vc_enough_space (Fvpl->vpl_pgdesc[i], tlen) )
@@ -881,7 +937,8 @@ _vc_rpfheap (VRelList curvrl, Relation onerel,
        }
        if ( i == Fnpages )
            break;          /* can't move item anywhere */
-       ToVpd = Fvpl->vpl_pgdesc[i];
+       ToVpI = i;
+       ToVpd = Fvpl->vpl_pgdesc[ToVpI];
        ToBuf = ReadBuffer(onerel, ToVpd->vpd_blkno);
        ToPage = BufferGetPage(ToBuf);
        /* if this page was not used before - clean it */