SHOW STATUS does not anymore change local status variables (except com_show_status). Global status variables are still updated.

SHOW STATUS are not anymore put in slow query log because of no index usage.

Implemntation done by removing orig_sql_command and moving logic of SHOW STATUS to mysql_excute_command()
This simplifies code and allows us to remove some if statements all over the code.

Upgraded uc_update_queries[] to sql_command_flags and added more bitmaps to better categorize commands.
This allowed some overall simplifaction when testing sql_command.

Fixes bugs:
Bug#10210: running SHOW STATUS increments counters it shouldn't
Bug#19764: SHOW commands end up in the slow log as table scans


mysql-test/r/grant_cache.result:
  Fixed results after SHOW STATUS doesn't anymore affect status variables
mysql-test/r/information_schema.result:
  Added extra test to cover more code
mysql-test/r/query_cache.result:
  Remove resuts from previous tests
mysql-test/r/status.result:
  Added more tests for testing of last_query_cost and how SHOW STATUS affects status variables.
  (Bug#10210)
mysql-test/r/temp_table.result:
  Fixed results after SHOW STATUS doesn't anymore affect status variables
mysql-test/r/union.result:
  Fixed results after SHOW STATUS is not logged to slow query log
  (Bug#19764)
mysql-test/t/events_microsec.test:
  Disable warnings at init
mysql-test/t/information_schema.test:
  Added extra test to cover more code
mysql-test/t/query_cache.test:
  Remove resuts from previous tests
mysql-test/t/status.test:
  Added more tests for testing of last_query_cost and how SHOW STATUS affects status variables.
  (Bug #10210)
sql/mysql_priv.h:
  Added 'sql_command_flags'
sql/sql_class.cc:
  New function add_diff_to_status(), used to update global status variables when using SHOW STATUS
sql/sql_class.h:
  New function 'fill_information_schema_tables()'
  (One could not anymore use fill_derived_tables() for this as only_view_structures() is not relevant for information schema tables)
  Added defines for bit flags in sql_command_flags[]
sql/sql_lex.cc:
  Remove orig_sql_command
sql/sql_lex.h:
  Remove orig_sql_command
sql/sql_parse.cc:
  Rename uc_update_queries -> sql_command_flags.
  Enhanced 'sql_command_flags' to better classify SQL commands
  uc_update_queries[] != 0 is changed to (sql_command_flags[] & CF_CHANGES_DATA)
  lex->orig_sql_command == SQLCOM_END is changed to (sql_command_flags[lex->sql_command] & CF_STATUS_COMMAND) == 0)
  
  Simplify incrementing of thd->status_var.com_stat[] as we don't have to do special handling for SHOW commands.
  
  Split SQLCOM_SELECT handling in mysql_execute_command() to a separate function.
  Added special handling of SHOW STATUS commands in mysql_execute_command() and call common SQLCOM_SELECT handling.
  These changes allows us to easily fix that we save and restore status variables during execution of a SHOW STATUS command.
  Don't log SHOW STATUS commands to slow query log.
  
  This fixes Bug#10210 and Bug#19764 without adding additional 'if' code.
  (The new code is faster than the original as we now have fewer if's than before)
sql/sql_prepare.cc:
  Clean up prepare-check handling of SQLCOM commands by using sql_command_flags[]
  This simplifes code and ensures that code works even if someone forgets to put a new status commands into the switch statement.
sql/sql_select.cc:
  Remove special handling of SHOW STATUS.
  (This is now done in SQLCOM_SHOW_STATUS part in mysql_execute_command())
sql/sql_show.cc:
  Remove orig_sql_command
  Only change sql_command during 'open_normal_and_derived_tables()' (for views) and not for the full duration of generating data.
  Changed 'show status' to use thd->initial_status_var to ensure that the current statement is not affecting the to-be-used values.
  Use thd->fill_information_schema_tables() instead of 'thd->fill_derived_tables()' as the later wrongly checks the value of sql_command.
sql/sql_yacc.yy:
  Remove usage of orig_sql_command.
  One side effect of this is that we need to test for cursors if the current command is a SELECT or a SHOW command.
sql/structs.h:
  Updated comment

1 files changed, 8 insertions, 8 deletions

diff --git a/mysql-test/r/grant_cache.result b/mysql-test/r/grant_cache.result
index 925a5918c1b..2c6840d77d0 100644
--- a/mysql-test/r/grant_cache.result
+++ b/mysql-test/r/grant_cache.result
@@ -60,7 +60,7 @@ Variable_name	Value
 Qcache_hits	0
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	5
+Qcache_not_cached	0
 select "user1";
 user1
 user1
@@ -72,7 +72,7 @@ Variable_name	Value
 Qcache_hits	0
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	9
+Qcache_not_cached	1
 select * from t1;
 a	b	c
 1	1	1
@@ -85,7 +85,7 @@ Variable_name	Value
 Qcache_hits	1
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	12
+Qcache_not_cached	1
 select a from t1 ;
 a
 1
@@ -98,7 +98,7 @@ Variable_name	Value
 Qcache_hits	2
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	15
+Qcache_not_cached	1
 select c from t1;
 c
 1
@@ -111,7 +111,7 @@ Variable_name	Value
 Qcache_hits	3
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	18
+Qcache_not_cached	1
 show grants for current_user();
 Grants for @localhost
 GRANT USAGE ON *.* TO ''@'localhost'
@@ -144,7 +144,7 @@ Variable_name	Value
 Qcache_hits	7
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	22
+Qcache_not_cached	2
 select "user3";
 user3
 user3
@@ -168,7 +168,7 @@ Variable_name	Value
 Qcache_hits	7
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	30
+Qcache_not_cached	7
 select "user4";
 user4
 user4
@@ -198,7 +198,7 @@ Variable_name	Value
 Qcache_hits	8
 show status like "Qcache_not_cached";
 Variable_name	Value
-Qcache_not_cached	34
+Qcache_not_cached	8
 set names binary;
 delete from mysql.user where user in ("mysqltest_1","mysqltest_2","mysqltest_3");
 delete from mysql.db where user in ("mysqltest_1","mysqltest_2","mysqltest_3");