Update cost for hash and cached joins

The old code did not't correctly add TIME_FOR_COMPARE to rows that are
part of the scan that will be compared with the attached where clause.

Now the cost calculation for hash join and full join cache join are
identical except for HASH_FANOUT (10%)

The cost for a join with keys is now also uniform.
The total cost for a using a key for lookup is calculated in one place as:

(cost_of_finding_rows_through_key(records) + records/TIME_FOR_COMPARE)*
record_count_of_previous_row_combinations + startup_cost

startup_cost is the cost of a creating a temporary table (if needed)

Best_cost now includes the cost of comparing all WHERE clauses and also
cost of joining with previous row combinations.

Other things:
- Optimizer trace is now printing the total costs, including testing the
  WHERE clause (TIME_FOR_COMPARE) and comparing with all previous rows.
- In optimizer trace, include also total cost of query together with the
  final join order. This makes it easier to find out where the cost was
  calculated.
- Old code used filter even if the cost for it was higher than not using a
  filter. This is not corrected.
- When rebasing on 10.11, I noticed some changes to access_cost_factor
  calculation. These changes was not picked as the coming changes
  to filtering will make that code obsolete.

1 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/suite/maria/mrr.result b/mysql-test/suite/maria/mrr.result
index cc42f81e3c4..066f1a50aab 100644
--- a/mysql-test/suite/maria/mrr.result
+++ b/mysql-test/suite/maria/mrr.result
@@ -404,8 +404,8 @@ FROM t1 AS table1, t2 AS table2
 WHERE
 table1.col_varchar_1024_latin1_key = table2.col_varchar_10_latin1 AND table1.pk<>0 ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	table2	ALL	NULL	NULL	NULL	NULL	2	
-1	SIMPLE	table1	ALL	PRIMARY,col_varchar_1024_latin1_key	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	table2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	table1	ref	PRIMARY,col_varchar_1024_latin1_key	col_varchar_1024_latin1_key	1027	test.table2.col_varchar_10_latin1	2	Using index condition(BKA); Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
 SELECT count(*)
 FROM t1 AS table1, t2 AS table2
 WHERE