Remove nbtree BTreeTupleSetAltHeapTID() function.

Since heap TID is supposed to be just another key attribute to the
implementation, it doesn't make much sense to have separate
BTreeTupleSetNAtts() and BTreeTupleSetAltHeapTID() functions.  Merge the
two functions together.  This slightly simplifies _bt_truncate().

diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 1675298f73dea3748b1325ae958aff42e7c3c33f..cbd4ec3b39e25e0e40593754b77273d42e43656d 100644 (file)
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -2413,7 +2413,7 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
    left_item = (IndexTuple) palloc(left_item_sz);
    left_item->t_info = left_item_sz;
    BTreeTupleSetDownLink(left_item, lbkno);
-   BTreeTupleSetNAtts(left_item, 0);
+   BTreeTupleSetNAtts(left_item, 0, false);
 
    /*
     * Create downlink item for right page.  The key for it is obtained from
@@ -2571,7 +2571,7 @@ _bt_pgaddtup(Page page,
    {
        trunctuple = *itup;
        trunctuple.t_info = sizeof(IndexTupleData);
-       BTreeTupleSetNAtts(&trunctuple, 0);
+       BTreeTupleSetNAtts(&trunctuple, 0, false);
        itup = &trunctuple;
        itemsize = sizeof(IndexTupleData);
    }

diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c
index 29a6f5ade614f61f113a72f240094c0bfc23062f..9d249f7a6b65b903d0f1941dc3fd61161f8d43fd 100644 (file)
--- a/src/backend/access/nbtree/nbtsort.c
+++ b/src/backend/access/nbtree/nbtsort.c
@@ -771,7 +771,7 @@ _bt_sortaddtup(Page page,
    {
        trunctuple = *itup;
        trunctuple.t_info = sizeof(IndexTupleData);
-       BTreeTupleSetNAtts(&trunctuple, 0);
+       BTreeTupleSetNAtts(&trunctuple, 0, false);
        itup = &trunctuple;
        itemsize = sizeof(IndexTupleData);
    }
@@ -1045,7 +1045,7 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup,
        Assert(state->btps_lowkey == NULL);
        state->btps_lowkey = palloc0(sizeof(IndexTupleData));
        state->btps_lowkey->t_info = sizeof(IndexTupleData);
-       BTreeTupleSetNAtts(state->btps_lowkey, 0);
+       BTreeTupleSetNAtts(state->btps_lowkey, 0, false);
    }
 
    /*

diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 86cec248593cf248b06019476cb5afc3cb89a480..08d7201f196549d0cd6449a316aa8385ec4d45c0 100644 (file)
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -2239,7 +2239,7 @@ _bt_truncate(Relation rel, IndexTuple lastleft, IndexTuple firstright,
     */
    if (keepnatts <= nkeyatts)
    {
-       BTreeTupleSetNAtts(pivot, keepnatts);
+       BTreeTupleSetNAtts(pivot, keepnatts, false);
        return pivot;
    }
 
@@ -2262,11 +2262,13 @@ _bt_truncate(Relation rel, IndexTuple lastleft, IndexTuple firstright,
    /* Cannot leak memory here */
    pfree(pivot);
 
-   /* Store heap TID in enlarged pivot tuple */
+   /*
+    * Store all of firstright's key attribute values plus a tiebreaker heap
+    * TID value in enlarged pivot tuple
+    */
    tidpivot->t_info &= ~INDEX_SIZE_MASK;
    tidpivot->t_info |= newsize;
-   BTreeTupleSetNAtts(tidpivot, nkeyatts);
-   BTreeTupleSetAltHeapTID(tidpivot);
+   BTreeTupleSetNAtts(tidpivot, nkeyatts, true);
    pivotheaptid = BTreeTupleGetHeapTID(tidpivot);
 
    /*

diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index 5f67fc04e0962ff6d6037da8978186af154ebfc2..072a41ef8bfeb27c2eaa5c20e8f8ddb78ca26a7f 100644 (file)
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -460,32 +460,28 @@ BTreeTupleSetDownLink(IndexTuple pivot, BlockNumber blkno)
    )
 
 /*
- * Set number of attributes in tuple, making it into a pivot tuple
+ * Set number of key attributes in tuple.
+ *
+ * The heap TID tiebreaker attribute bit may also be set here, indicating that
+ * a heap TID value will be stored at the end of the tuple (i.e. using the
+ * special pivot tuple representation).
  */
 static inline void
-BTreeTupleSetNAtts(IndexTuple itup, int natts)
+BTreeTupleSetNAtts(IndexTuple itup, uint16 nkeyatts, bool heaptid)
 {
-   Assert(natts <= INDEX_MAX_KEYS);
+   Assert(nkeyatts <= INDEX_MAX_KEYS);
+   Assert((nkeyatts & BT_RESERVED_OFFSET_MASK) == 0);
+   Assert(!heaptid || nkeyatts > 0);
+   Assert(!BTreeTupleIsPivot(itup) || nkeyatts == 0);
 
    itup->t_info |= INDEX_ALT_TID_MASK;
-   /* BT_IS_POSTING bit may be unset -- tuple always becomes a pivot tuple */
-   ItemPointerSetOffsetNumber(&itup->t_tid, natts);
-   Assert(BTreeTupleIsPivot(itup));
-}
-
-/*
- * Set the bit indicating heap TID attribute present in pivot tuple
- */
-static inline void
-BTreeTupleSetAltHeapTID(IndexTuple pivot)
-{
-   OffsetNumber existing;
 
-   Assert(BTreeTupleIsPivot(pivot));
+   if (heaptid)
+       nkeyatts |= BT_PIVOT_HEAP_TID_ATTR;
 
-   existing = ItemPointerGetOffsetNumberNoCheck(&pivot->t_tid);
-   ItemPointerSetOffsetNumber(&pivot->t_tid,
-                              existing | BT_PIVOT_HEAP_TID_ATTR);
+   /* BT_IS_POSTING bit is deliberately unset here */
+   ItemPointerSetOffsetNumber(&itup->t_tid, nkeyatts);
+   Assert(BTreeTupleIsPivot(itup));
 }
 
 /*
@@ -505,7 +501,7 @@ static inline void
 BTreeTupleSetTopParent(IndexTuple leafhikey, BlockNumber blkno)
 {
    ItemPointerSetBlockNumber(&leafhikey->t_tid, blkno);
-   BTreeTupleSetNAtts(leafhikey, 0);
+   BTreeTupleSetNAtts(leafhikey, 0, false);
 }
 
 /*