Fixed cost calculations for materialized tables

One effect of this change in the test suite is that tests with very few
rows changed to use sub queries instead of materialization. This is
correct and expected as for these the materialization overhead is too high.

A lot of tests where fixed to still use materialization by adding a
few rows to the tables (most tests has only 2-3 rows and are thus easily
affected when cost computations are changed).

Other things:
- Added more variables to TMPTABLE_COSTS for better cost calculation
- Added cost of copying rows to TMPTABLE_COSTS lookup and write
- Added THD::optimizer_cache_hit_ratio for easier cost calculations
- Added DISK_FAST_READ_SIZE to be used when calculating costs when
  reading big blocks from a disk

1 files changed, 9 insertions, 9 deletions

diff --git a/mysql-test/main/order_by.result b/mysql-test/main/order_by.result
index af379cf4aae..95ec2573463 100644
--- a/mysql-test/main/order_by.result
+++ b/mysql-test/main/order_by.result
@@ -4408,7 +4408,7 @@ CREATE TABLE t1 (a INT, b int, primary key(a));
 CREATE TABLE t2 (a INT, b INT);
 INSERT INTO t1 (a,b) VALUES (58,1),(96,2),(273,3),(23,4),(231,5),(525,6),
 (2354,7),(321421,3),(535,2),(4535,3);
-INSERT INTO t2 (a,b) VALUES (58,3),(96,3),(273,3);
+INSERT INTO t2 (a,b) VALUES (58,3),(96,3),(273,3),(1000,1000),(2000,2000);
 # Join order should have the SJM scan table as the first table for both
 # the queries with GROUP BY and ORDER BY clause.
 EXPLAIN SELECT t1.a
@@ -4416,9 +4416,9 @@ FROM t1
 WHERE t1.a IN (SELECT a FROM t2 WHERE b=3)
 ORDER BY t1.a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	Using filesort
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using filesort
 1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using index
-2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
 EXPLAIN FORMAT=JSON SELECT t1.a
 FROM t1
 WHERE t1.a IN (SELECT a FROM t2 WHERE b=3)
@@ -4436,7 +4436,7 @@ EXPLAIN
               "table_name": "<subquery2>",
               "access_type": "ALL",
               "possible_keys": ["distinct_key"],
-              "rows": 3,
+              "rows": 5,
               "filtered": 100,
               "materialized": {
                 "unique": 1,
@@ -4447,7 +4447,7 @@ EXPLAIN
                       "table": {
                         "table_name": "t2",
                         "access_type": "ALL",
-                        "rows": 3,
+                        "rows": 5,
                         "filtered": 100,
                         "attached_condition": "t2.b = 3 and t2.a is not null"
                       }
@@ -4489,9 +4489,9 @@ FROM t1
 WHERE t1.a IN (SELECT a FROM t2 WHERE b=3)
 GROUP BY t1.a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	Using filesort
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using filesort
 1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	
-2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
 EXPLAIN FORMAT=JSON SELECT t1.a, group_concat(t1.b)
 FROM t1
 WHERE t1.a IN (SELECT a FROM t2 WHERE b=3)
@@ -4509,7 +4509,7 @@ EXPLAIN
               "table_name": "<subquery2>",
               "access_type": "ALL",
               "possible_keys": ["distinct_key"],
-              "rows": 3,
+              "rows": 5,
               "filtered": 100,
               "materialized": {
                 "unique": 1,
@@ -4520,7 +4520,7 @@ EXPLAIN
                       "table": {
                         "table_name": "t2",
                         "access_type": "ALL",
-                        "rows": 3,
+                        "rows": 5,
                         "filtered": 100,
                         "attached_condition": "t2.b = 3 and t2.a is not null"
                       }