diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/bufpage.c
index c0095c7ba18..61e7437f8ff 100644
--- a/src/backend/storage/page/bufpage.c
+++ b/src/backend/storage/page/bufpage.c
@@ -404,10 +404,9 @@ PageRestoreTempPage(Page tempPage, Page oldPage)
*/
typedef struct itemIdSortData
{
- int offsetindex; /* linp array index */
- int itemoff; /* page offset of item data */
- Size alignedlen; /* MAXALIGN(item data len) */
- ItemIdData olditemid; /* used only in PageIndexMultiDelete */
+ uint16 offsetindex; /* linp array index */
+ int16 itemoff; /* page offset of item data */
+ uint16 alignedlen; /* MAXALIGN(item data len) */
} itemIdSortData;
typedef itemIdSortData *itemIdSort;
@@ -419,6 +418,38 @@ itemoffcompare(const void *itemidp1, const void *itemidp2)
((itemIdSort) itemidp1)->itemoff;
}
+/*
+ * After removing or marking some line pointers unused, move the tuples to
+ * remove the gaps caused by the removed items.
+ */
+static void
+compactify_tuples(itemIdSort itemidbase, int nitems, Page page)
+{
+ PageHeader phdr = (PageHeader) page;
+ Offset upper;
+ int i;
+
+ /* sort itemIdSortData array into decreasing itemoff order */
+ qsort((char *) itemidbase, nitems, sizeof(itemIdSortData),
+ itemoffcompare);
+
+ upper = phdr->pd_special;
+ for (i = 0; i < nitems; i++)
+ {
+ itemIdSort itemidptr = &itemidbase[i];
+ ItemId lp;
+
+ lp = PageGetItemId(page, itemidptr->offsetindex + 1);
+ upper -= itemidptr->alignedlen;
+ memmove((char *) page + upper,
+ (char *) page + itemidptr->itemoff,
+ itemidptr->alignedlen);
+ lp->lp_off = upper;
+ }
+
+ phdr->pd_upper = upper;
+}
+
/*
* PageRepairFragmentation
*
@@ -441,7 +472,6 @@ PageRepairFragmentation(Page page)
nunused;
int i;
Size totallen;
- Offset upper;
/*
* It's worth the trouble to be more paranoid here than in most places,
@@ -515,24 +545,7 @@ PageRepairFragmentation(Page page)
errmsg("corrupted item lengths: total %u, available space %u",
(unsigned int) totallen, pd_special - pd_lower)));
- /* sort itemIdSortData array into decreasing itemoff order */
- qsort((char *) itemidbase, nstorage, sizeof(itemIdSortData),
- itemoffcompare);
-
- /* compactify page */
- upper = pd_special;
-
- for (i = 0, itemidptr = itemidbase; i < nstorage; i++, itemidptr++)
- {
- lp = PageGetItemId(page, itemidptr->offsetindex + 1);
- upper -= itemidptr->alignedlen;
- memmove((char *) page + upper,
- (char *) page + itemidptr->itemoff,
- itemidptr->alignedlen);
- lp->lp_off = upper;
- }
-
- ((PageHeader) page)->pd_upper = upper;
+ compactify_tuples(itemidbase, nstorage, page);
}
/* Set hint bit for PageAddItem */
@@ -782,13 +795,12 @@ PageIndexMultiDelete(Page page, OffsetNumber *itemnos, int nitems)
Offset pd_upper = phdr->pd_upper;
Offset pd_special = phdr->pd_special;
itemIdSortData itemidbase[MaxIndexTuplesPerPage];
+ ItemIdData newitemids[MaxIndexTuplesPerPage];
itemIdSort itemidptr;
ItemId lp;
int nline,
nused;
- int i;
Size totallen;
- Offset upper;
Size size;
unsigned offset;
int nextitm;
@@ -857,9 +869,9 @@ PageIndexMultiDelete(Page page, OffsetNumber *itemnos, int nitems)
{
itemidptr->offsetindex = nused; /* where it will go */
itemidptr->itemoff = offset;
- itemidptr->olditemid = *lp;
itemidptr->alignedlen = MAXALIGN(size);
totallen += itemidptr->alignedlen;
+ newitemids[nused] = *lp;
itemidptr++;
nused++;
}
@@ -875,26 +887,15 @@ PageIndexMultiDelete(Page page, OffsetNumber *itemnos, int nitems)
errmsg("corrupted item lengths: total %u, available space %u",
(unsigned int) totallen, pd_special - pd_lower)));
- /* sort itemIdSortData array into decreasing itemoff order */
- qsort((char *) itemidbase, nused, sizeof(itemIdSortData),
- itemoffcompare);
-
- /* compactify page and install new itemids */
- upper = pd_special;
-
- for (i = 0, itemidptr = itemidbase; i < nused; i++, itemidptr++)
- {
- lp = PageGetItemId(page, itemidptr->offsetindex + 1);
- upper -= itemidptr->alignedlen;
- memmove((char *) page + upper,
- (char *) page + itemidptr->itemoff,
- itemidptr->alignedlen);
- *lp = itemidptr->olditemid;
- lp->lp_off = upper;
- }
-
+ /*
+ * Looks good. Overwrite the line pointers with the copy, from which we've
+ * removed all the unused items.
+ */
+ memcpy(phdr->pd_linp, newitemids, nused * sizeof(ItemIdData));
phdr->pd_lower = SizeOfPageHeaderData + nused * sizeof(ItemIdData);
- phdr->pd_upper = upper;
+
+ /* and compactify the tuple data */
+ compactify_tuples(itemidbase, nused, page);
}
/*
@@ -1000,7 +1001,6 @@ PageIndexDeleteNoCompact(Page page, OffsetNumber *itemnos, int nitems)
itemIdSort itemidptr;
int i;
Size totallen;
- Offset upper;
/*
* Scan the page taking note of each item that we need to preserve.
@@ -1012,7 +1012,8 @@ PageIndexDeleteNoCompact(Page page, OffsetNumber *itemnos, int nitems)
*/
itemidptr = itemidbase;
totallen = 0;
- for (i = 0; i < nline; i++, itemidptr++)
+ PageClearHasFreeLinePointers(page);
+ for (i = 0; i < nline; i++)
{
ItemId lp;
@@ -1024,13 +1025,15 @@ PageIndexDeleteNoCompact(Page page, OffsetNumber *itemnos, int nitems)
itemidptr->itemoff = ItemIdGetOffset(lp);
itemidptr->alignedlen = MAXALIGN(ItemIdGetLength(lp));
totallen += itemidptr->alignedlen;
+ itemidptr++;
}
else
{
- itemidptr->itemoff = 0;
- itemidptr->alignedlen = 0;
+ PageSetHasFreeLinePointers(page);
+ ItemIdSetUnused(lp);
}
}
+ nline = itemidptr - itemidbase;
/* By here, there are exactly nline elements in itemidbase array */
if (totallen > (Size) (pd_special - pd_lower))
@@ -1039,38 +1042,11 @@ PageIndexDeleteNoCompact(Page page, OffsetNumber *itemnos, int nitems)
errmsg("corrupted item lengths: total %u, available space %u",
(unsigned int) totallen, pd_special - pd_lower)));
- /* sort itemIdSortData array into decreasing itemoff order */
- qsort((char *) itemidbase, nline, sizeof(itemIdSortData),
- itemoffcompare);
-
/*
* Defragment the data areas of each tuple, being careful to preserve
* each item's position in the linp array.
*/
- upper = pd_special;
- PageClearHasFreeLinePointers(page);
- for (i = 0, itemidptr = itemidbase; i < nline; i++, itemidptr++)
- {
- ItemId lp;
-
- lp = PageGetItemId(page, itemidptr->offsetindex + 1);
- if (itemidptr->alignedlen == 0)
- {
- PageSetHasFreeLinePointers(page);
- ItemIdSetUnused(lp);
- continue;
- }
- upper -= itemidptr->alignedlen;
- memmove((char *) page + upper,
- (char *) page + itemidptr->itemoff,
- itemidptr->alignedlen);
- lp->lp_off = upper;
- /* lp_flags and lp_len remain the same as originally */
- }
-
- /* Set the new page limits */
- phdr->pd_upper = upper;
- phdr->pd_lower = SizeOfPageHeaderData + i * sizeof(ItemIdData);
+ compactify_tuples(itemidbase, nline, page);
}
}