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, 1 insertions, 0 deletions

diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
index d4df8c6468f..df5cd37c3c6 100644
--- a/sql/sql_plugin.h
+++ b/sql/sql_plugin.h
@@ -24,6 +24,7 @@
 #define SHOW_always_last SHOW_KEY_CACHE_LONG, \
             SHOW_HAVE, SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, \
             SHOW_LONG_NOFLUSH, SHOW_LEX_STRING, SHOW_ATOMIC_COUNTER_UINT32_T, \
+            SHOW_OPTIMIZER_COST, \
       /* SHOW_*_STATUS must be at the end, SHOW_LONG_STATUS being first */ \
             SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, SHOW_LONGLONG_STATUS, \
             SHOW_UINT32_STATUS