Added support of null keys in HEAP tables

Added ORDER BY optimization

1 files changed, 9 insertions, 0 deletions

diff --git a/sql/ha_isam.cc b/sql/ha_isam.cc
index a96f42c202f..4b8c40f8fe6 100644
--- a/sql/ha_isam.cc
+++ b/sql/ha_isam.cc
@@ -109,6 +109,15 @@ int ha_isam::index_read_idx(byte * buf, uint index, const byte * key,
   return !error ? 0 : my_errno ? my_errno : -1;
 }
 
+int ha_isam::index_read_last(byte * buf, const byte * key, uint key_len)
+{
+  statistic_increment(ha_read_key_count,&LOCK_status);
+  int error=nisam_rkey(file, buf, active_index, key, key_len,
+		       HA_READ_PREFIX_LAST);
+  table->status=error ? STATUS_NOT_FOUND: 0;
+  return !error ? 0 : my_errno ? my_errno : -1;
+}
+
 int ha_isam::index_next(byte * buf)
 {
   statistic_increment(ha_read_next_count,&LOCK_status);