Merge bk-internal.mysql.com:/home/bk/mysql-5.1-runtime

into  jabberwock.site:/home/dlenev/mysql-5.1-bg18437


sql/ha_ndbcluster.cc:
  Auto merged
sql/ha_partition.cc:
  Auto merged
sql/log_event.cc:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/sql_insert.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_trigger.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged
sql/table.cc:
  Auto merged
sql/sql_table.cc:
  Manual merge.

1 files changed, 21 insertions, 0 deletions

diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index c0257e08537..037f6e0b8bb 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -4666,6 +4666,27 @@ int ha_partition::extra(enum ha_extra_function operation)
      */
     break;
   }
+  case HA_EXTRA_WRITE_CAN_REPLACE:
+  case HA_EXTRA_WRITE_CANNOT_REPLACE:
+  {
+    /*
+      Informs handler that write_row() can replace rows which conflict
+      with row being inserted by PK/unique key without reporting error
+      to the SQL-layer.
+
+      This optimization is not safe for partitioned table in general case
+      since we may have to put new version of row into partition which is
+      different from partition in which old version resides (for example
+      when we partition by non-PK column or by some column which is not
+      part of unique key which were violated).
+      And since NDB which is the only engine at the moment that supports
+      this optimization handles partitioning on its own we simple disable
+      it here. (BTW for NDB this optimization is safe since it supports
+      only KEY partitioning and won't use this optimization for tables
+      which have additional unique constraints).
+    */
+    break;
+  }
   default:
   {
     /* Temporary crash to discover what is wrong */