heapam: Don't re-inquire block number for each tuple during pruning.

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:

diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index 1794cfd8d9aab2c4cd4bb25a587a69e7b376f4d4..08953f6f0ac11197e09a8e97c8251d2724dfc498 100644 (file)
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -44,6 +44,7 @@ typedef struct
 
 /* Local functions */
 static int heap_prune_chain(Relation relation, Buffer buffer,
+                            BlockNumber blockno,
                             OffsetNumber rootoffnum,
                             TransactionId OldestXmin,
                             PruneState *prstate);
@@ -185,6 +186,7 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin,
    OffsetNumber offnum,
                maxoff;
    PruneState  prstate;
+   BlockNumber blockno = BufferGetBlockNumber(buffer);
 
    /*
     * Our strategy is to scan the page and make lists of items to change,
@@ -220,7 +222,8 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin,
            continue;
 
        /* Process this item or chain of items */
-       ndeleted += heap_prune_chain(relation, buffer, offnum,
+       ndeleted += heap_prune_chain(relation, buffer,
+                                    blockno, offnum,
                                     OldestXmin,
                                     &prstate);
    }
@@ -349,7 +352,9 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin,
  * Returns the number of tuples (to be) deleted from the page.
  */
 static int
-heap_prune_chain(Relation relation, Buffer buffer, OffsetNumber rootoffnum,
+heap_prune_chain(Relation relation, Buffer buffer,
+                BlockNumber blockno,
+                OffsetNumber rootoffnum,
                 TransactionId OldestXmin,
                 PruneState *prstate)
 {
@@ -379,7 +384,7 @@ heap_prune_chain(Relation relation, Buffer buffer, OffsetNumber rootoffnum,
 
        tup.t_data = htup;
        tup.t_len = ItemIdGetLength(rootlp);
-       ItemPointerSet(&(tup.t_self), BufferGetBlockNumber(buffer), rootoffnum);
+       ItemPointerSet(&(tup.t_self), blockno, rootoffnum);
 
        if (HeapTupleHeaderIsHeapOnly(htup))
        {