TEMPORARY PUSH: Changing all cost calculation to be given in ms10.7-selectivity-old

- Added tests/check_costs.pl, a tool to verify optimizer cost calculations.
  - Most costs has been found with this program. All steps to calculate
    the new costs are documented in Docs/optimizer.costs
- User optimizer_cost variables are given in usec (as individual
  costs can be very small). Internally they are stored in ms.
- Changed DISK_READ_COST (was DISK_SEEK_BASE_COST) from a hard disk cost
  (9 ms) to common SSD cost (400MB/sec).
- Changed the following handler functions to return IO_AND_CPU_COST.
  This makes it easy to apply different cost modifiers in ha_..time()
  functions for io and cpu costs.
  - scan_time()
  - rndpos_time()
  - keyread_time()
- Enhanched keyread_time() to calculate the full cost of reading of a set
  of keys with a given number of ranges and optionall number of blocks that
  need to be accessed.
- Removed read_time() as keyread_time() + rndpos_time() is the same thing.
- Added the following new optimizer_variables:
  - optimizer_scan_lookup_cost
  - optimizer_row_lookup_cost
  - optimizer_index_lookup_cost
  - optimizer_disk_read_cost
- Added include/my_tracker.h  ; Useful include file to quickly test costs
  of a function.
- Tuned sequence and heap engine costs (rest will be done in an updated
  commit)

1 files changed, 41 insertions, 0 deletions

diff --git a/include/my_tracker.h b/include/my_tracker.h
new file mode 100644
index 00000000000..88cefe5ef5d
--- /dev/null
+++ b/include/my_tracker.h
@@ -0,0 +1,41 @@
+/* Copyright (c) 2022, MariaDB Corporation.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; version 2 of the License.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/*
+  Trivial framework to add a tracker to a C function
+*/
+
+#include "my_rdtsc.h"
+
+struct my_time_tracker
+{
+  ulonglong counter;
+  ulonglong cycles;
+};
+
+#ifdef HAVE_TIME_TRACKING
+#define START_TRACKING ulonglong my_start_time= my_timer_cycles()
+#define END_TRACKING(var) \
+  { \
+     ulonglong my_end_time= my_timer_cycles();                     \
+     (var)->counter++;                                             \
+     (var)->cycles+= (unlikely(my_end_time < my_start_time) ?      \
+                     my_end_time - my_start_time + ULONGLONG_MAX : \
+                     my_end_time - my_start_time);                 \
+  }
+#else
+#define START_TRACKING
+#define END_TRACKING(var) do { } while(0)
+#endif