Added thread variable max_seeks_for_key

Change optimizer to prefer key lookups before table scan
Change table scans to be done after tables with constrains on scanned table 


mysql-test/r/distinct.result:
  Update results
mysql-test/r/group_by.result:
  Update results
mysql-test/r/heap.result:
  Update results
mysql-test/r/join.result:
  Update results
mysql-test/r/key_diff.result:
  Update results
mysql-test/r/myisam.result:
  Update results
mysql-test/r/order_by.result:
  Update results
mysql-test/r/select_safe.result:
  Update results
mysql-test/t/distinct.test:
  Change test to be repeatable
mysql-test/t/join.test:
  Change test to be repeatable
mysql-test/t/select_safe.test:
  Add tests for MAX_SEEKS_FOR_KEY
sql/handler.h:
  Optimize structure for 64 bit machines (and to avoid problems with gdb)
sql/item_cmpfunc.cc:
  Initialize not_null_tables_cache properly
sql/mysqld.cc:
  Added max_seeks_for_key
sql/set_var.cc:
  Added max_seeks_for_key
sql/sql_class.h:
  Added max_seeks_for_key
sql/sql_select.cc:
  Added max_seeks_for_key
  Change optimizer to prefer key lookups before table scan.
  Change table scans to be done after tables with constrains on scanned table

1 files changed, 1 insertions, 1 deletions

diff --git a/mysql-test/r/heap.result b/mysql-test/r/heap.result
index d8905085e34..a04ddf3f302 100644
--- a/mysql-test/r/heap.result
+++ b/mysql-test/r/heap.result
@@ -166,7 +166,7 @@ alter table t1 add column new_col char(1) not null, add key (btn,new_col), drop
 update t1 set new_col=btn;
 explain select * from t1 where btn="a";
 table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	Using where
+t1	ALL	btn	NULL	NULL	NULL	11	Using where
 explain select * from t1 where btn="a" and new_col="a";
 table	type	possible_keys	key	key_len	ref	rows	Extra
 t1	ref	btn	btn	11	const,const	10	Using where