Merge pull request #2341 from wiredtiger/SERVER-21553

SERVER-21553 Enable fast-path truncate after splits.

2 files changed, 14 insertions, 11 deletions

diff --git a/src/btree/bt_delete.c b/src/btree/bt_delete.c
index dc9352ec981..760954a7fea 100644
--- a/src/btree/bt_delete.c
+++ b/src/btree/bt_delete.c
@@ -102,22 +102,15 @@ __wt_delete_page(WT_SESSION_IMPL *session, WT_REF *ref, bool *skipp)
 	 * out is to check the on-page cell type for the page, cells for leaf
 	 * pages that have no overflow items are special.
 	 *
-	 * In some cases, the reference address may not reference an on-page
-	 * cell (for example, some combination of page splits), in which case
-	 * we can't check the original cell value and we fail.
-	 *
 	 * To look at an on-page cell, we need to look at the parent page, and
 	 * that's dangerous, our parent page could change without warning if
 	 * the parent page were to split, deepening the tree.  It's safe: the
 	 * page's reference will always point to some valid page, and if we find
 	 * any problems we simply fail the fast-delete optimization.
-	 *
-	 * !!!
-	 * I doubt it's worth the effort, but we could copy the cell's type into
-	 * the reference structure, and then we wouldn't need an on-page cell.
 	 */
 	parent = ref->home;
-	if (__wt_off_page(parent, ref->addr) ||
+	if (__wt_off_page(parent, ref->addr) ?
+	    ((WT_ADDR *)ref->addr)->type != WT_ADDR_LEAF_NO :
 	    __wt_cell_type_raw(ref->addr) != WT_CELL_ADDR_LEAF_NO)
 		goto err;
 
diff --git a/src/btree/bt_split.c b/src/btree/bt_split.c
index 35c3bfea711..3e49d177ca6 100644
--- a/src/btree/bt_split.c
+++ b/src/btree/bt_split.c
@@ -340,8 +340,18 @@ __split_ref_move(WT_SESSION_IMPL *session, WT_PAGE *from_home,
 			return (ret);
 		}
 		addr->size = (uint8_t)unpack.size;
-		addr->type =
-		    unpack.raw == WT_CELL_ADDR_INT ? WT_ADDR_INT : WT_ADDR_LEAF;
+		switch (unpack.raw) {
+		case WT_CELL_ADDR_INT:
+			addr->type = WT_ADDR_INT;
+			break;
+		case WT_CELL_ADDR_LEAF:
+			addr->type = WT_ADDR_LEAF;
+			break;
+		case WT_CELL_ADDR_LEAF_NO:
+			addr->type = WT_ADDR_LEAF_NO;
+			break;
+		WT_ILLEGAL_VALUE(session);
+		}
 		ref->addr = addr;
 	}