Update vacuum comments.

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 3af6f6b183b6d9f5d104fba61a069444adea2d1a..56fa2d4b9cf18bd7a5b4e53686ab6b0e66da0c85 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 1.135 2000/01/15 22:43:22 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.136 2000/01/19 22:23:00 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -285,6 +285,9 @@ vc_getrels(NameData *VacRelP)
 
        if (NameStr(*VacRelP))
        {
+       /* we could use the cache here, but it is clearer to use
+        *  scankeys for both vacuum cases, bjm 2000/01/19
+        */
                ScanKeyEntryInitialize(&key, 0x0, Anum_pg_class_relname,
                                                           F_NAMEEQ,
                                                           PointerGetDatum(NameStr(*VacRelP)));
@@ -766,7 +769,6 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
                                        }
                                        else if (!TransactionIdIsInProgress(tuple.t_data->t_xmin))
                                        {
-
                                                /*
                                                 * Not Aborted, Not Committed, Not in Progress -
                                                 * so it's from crashed process. - vadim 11/26/96
@@ -817,7 +819,6 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
                                }
                                else if (!TransactionIdIsInProgress(tuple.t_data->t_xmax))
                                {
-
                                        /*
                                         * Not Aborted, Not Committed, Not in Progress - so it
                                         * from crashed process. - vadim 06/02/97
@@ -920,7 +921,8 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
                }
                else
                        dobufrel = true;
-               if (tempPage != (Page) NULL)
+
+       if (tempPage != (Page) NULL)
                {                                               /* Some tuples are gone */
                        PageRepairFragmentation(tempPage);
                        vpc->vpd_free = ((PageHeader) tempPage)->pd_upper - ((PageHeader) tempPage)->pd_lower;
@@ -1266,7 +1268,7 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                                                 * This means that in the middle of chain there was
                                                 * tuple updated by older (than XmaxRecent) xaction
                                                 * and this tuple is already deleted by me. Actually,
-                                                * upper part of chain should be removed and seems 
+                                                * upper part of chain should be removed and seems
                                                 * that this should be handled in vc_scanheap(), but
                                                 * it's not implemented at the moment and so we
                                                 * just stop shrinking here.
@@ -1307,9 +1309,10 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                                                        if (vc_enough_space(fraged_pages->vpl_pagedesc[i], tlen))
                                                                break;
                                                }
-                                               if (i == num_fraged_pages)              /* can't move item
-                                                                                                                * anywhere */
-                                               {
+
+                       /* can't move item anywhere */
+                                               if (i == num_fraged_pages)
+                       {
                                                        for (i = 0; i < num_vtmove; i++)
                                                        {
                                                                Assert(vtmove[i].vpd->vpd_offsets_used > 0);
@@ -1341,16 +1344,12 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                                        free_vtmove--;
                                        num_vtmove++;
 
-                                       /*
-                                        * All done ?
-                                        */
+                                       /* All done ? */
                                        if (!(tp.t_data->t_infomask & HEAP_UPDATED) ||
                                                tp.t_data->t_xmin < XmaxRecent)
                                                break;
 
-                                       /*
-                                        * Well, try to find tuple with old row version
-                                        */
+                                       /* Well, try to find tuple with old row version */
                                        for (;;)
                                        {
                                                Buffer          Pbuf;
@@ -1384,9 +1383,9 @@ vc_rpfheap(VRelStats *vacrelstats, Relation onerel,
                                                /*
                                                 * 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 
+                                                * 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 
+                                                * 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
@@ -1660,7 +1659,7 @@ failed to add item with len = %u to page %u (free space %u, nusd %u, noff %u)",
                                }
                        }
 
-               }                                               /* walk along page */
+               }               /* walk along page */
 
                if (offnum < maxoff && keep_tuples > 0)
                {
@@ -1683,9 +1682,9 @@ failed to add item with len = %u to page %u (free space %u, nusd %u, noff %u)",
                                        elog(ERROR, "HEAP_MOVED_IN was not expected (2)");
                                if (tuple.t_data->t_infomask & HEAP_MOVED_OFF)
                                {
-                                       if (chain_tuple_moved)          /* some chains was moved
-                                                                                                * while */
-                                       {                       /* cleaning this page */
+                                       /* some chains was moved while */
+                   if (chain_tuple_moved)
+                   {                   /* cleaning this page */
                                                Assert(vpc->vpd_offsets_free > 0);
                                                for (i = 0; i < vpc->vpd_offsets_free; i++)
                                                {
@@ -1831,9 +1830,7 @@ failed to add item with len = %u to page %u (free space %u, nusd %u, noff %u)",
                                                         vacrelstats->num_tuples, keep_tuples);
                }
 
-               /*
-                * clean moved tuples from last page in Nvpl list
-                */
+               /* clean moved tuples from last page in Nvpl list */
                if (vpc->vpd_blkno == blkno - 1 && vpc->vpd_offsets_free > 0)
                {
                        buf = ReadBuffer(onerel, vpc->vpd_blkno);