Commit 3ea68493 authored by Ingo Struewing's avatar Ingo Struewing
Browse files

Bug#28234 - global/session scope - documentation vs implementation 

Several system variables did not behave like system variables should do.
When trying to SET them or use them in SELECT, they were reported as
"unknown system variable". But they appeared in SHOW VARIABLES.

This has been fixed by removing the "fixed_vars" array of variables
and integrating the variables into the normal system variables chain.
All of these variables do now behave as read-only global-only
variables. Trying to SET them tells they are read-only, trying to
SELECT the session value tells they are global only. Selecting the
global value works. It delivers the same value as SHOW VARIABLES.
parent 91684ef0

mysql-test/r/variables-notembedded.result

+92 −0
Original line number Diff line number Diff line
@@ -15,3 +15,95 @@ slave_skip_errors 3,100,137,643,1752 
---- Clean Up ----

set global slave_net_timeout=default;

set global sql_slave_skip_counter= 0;



#

SHOW VARIABLES like 'log_slave_updates';

Variable_name	Value

log_slave_updates	OFF

SELECT @@session.log_slave_updates;

ERROR HY000: Variable 'log_slave_updates' is a GLOBAL variable

SELECT @@global.log_slave_updates;

@@global.log_slave_updates

0

SET @@session.log_slave_updates= true;

ERROR HY000: Variable 'log_slave_updates' is a read only variable

SET @@global.log_slave_updates= true;

ERROR HY000: Variable 'log_slave_updates' is a read only variable

#

SHOW VARIABLES like 'relay_log';

Variable_name	Value

relay_log	

SELECT @@session.relay_log;

ERROR HY000: Variable 'relay_log' is a GLOBAL variable

SELECT @@global.relay_log;

@@global.relay_log

NULL

SET @@session.relay_log= 'x';

ERROR HY000: Variable 'relay_log' is a read only variable

SET @@global.relay_log= 'x';

ERROR HY000: Variable 'relay_log' is a read only variable

#

SHOW VARIABLES like 'relay_log_index';

Variable_name	Value

relay_log_index	

SELECT @@session.relay_log_index;

ERROR HY000: Variable 'relay_log_index' is a GLOBAL variable

SELECT @@global.relay_log_index;

@@global.relay_log_index

NULL

SET @@session.relay_log_index= 'x';

ERROR HY000: Variable 'relay_log_index' is a read only variable

SET @@global.relay_log_index= 'x';

ERROR HY000: Variable 'relay_log_index' is a read only variable

#

SHOW VARIABLES like 'relay_log_info_file';

Variable_name	Value

relay_log_info_file	relay-log.info

SELECT @@session.relay_log_info_file;

ERROR HY000: Variable 'relay_log_info_file' is a GLOBAL variable

SELECT @@global.relay_log_info_file;

@@global.relay_log_info_file

relay-log.info

SET @@session.relay_log_info_file= 'x';

ERROR HY000: Variable 'relay_log_info_file' is a read only variable

SET @@global.relay_log_info_file= 'x';

ERROR HY000: Variable 'relay_log_info_file' is a read only variable

#

SHOW VARIABLES like 'relay_log_space_limit';

Variable_name	Value

relay_log_space_limit	0

SELECT @@session.relay_log_space_limit;

ERROR HY000: Variable 'relay_log_space_limit' is a GLOBAL variable

SELECT @@global.relay_log_space_limit;

@@global.relay_log_space_limit

0

SET @@session.relay_log_space_limit= 7;

ERROR HY000: Variable 'relay_log_space_limit' is a read only variable

SET @@global.relay_log_space_limit= 7;

ERROR HY000: Variable 'relay_log_space_limit' is a read only variable

#

SHOW VARIABLES like 'slave_load_tmpdir';

Variable_name	Value

slave_load_tmpdir	#

SELECT @@session.slave_load_tmpdir;

ERROR HY000: Variable 'slave_load_tmpdir' is a GLOBAL variable

SELECT @@global.slave_load_tmpdir;

@@global.slave_load_tmpdir

#

SET @@session.slave_load_tmpdir= 'x';

ERROR HY000: Variable 'slave_load_tmpdir' is a read only variable

SET @@global.slave_load_tmpdir= 'x';

ERROR HY000: Variable 'slave_load_tmpdir' is a read only variable

#

SHOW VARIABLES like 'slave_skip_errors';

Variable_name	Value

slave_skip_errors	3,100,137,643,1752

SELECT @@session.slave_skip_errors;

ERROR HY000: Variable 'slave_skip_errors' is a GLOBAL variable

SELECT @@global.slave_skip_errors;

@@global.slave_skip_errors

3,100,137,643,1752

SET @@session.slave_skip_errors= 7;

ERROR HY000: Variable 'slave_skip_errors' is a read only variable

SET @@global.slave_skip_errors= 7;

ERROR HY000: Variable 'slave_skip_errors' is a read only variable

mysql-test/r/variables.result

+339 −0
Original line number Diff line number Diff line
@@ -1011,3 +1011,342 @@ SET GLOBAL log_output = 0; 
ERROR 42000: Variable 'log_output' can't be set to the value of '0'



# -- End of Bug#34820.



#

SHOW VARIABLES like 'ft_max_word_len';

Variable_name	Value

ft_max_word_len	84

SELECT @@session.ft_max_word_len;

ERROR HY000: Variable 'ft_max_word_len' is a GLOBAL variable

SELECT @@global.ft_max_word_len;

@@global.ft_max_word_len

84

SET @@session.ft_max_word_len= 7;

ERROR HY000: Variable 'ft_max_word_len' is a read only variable

SET @@global.ft_max_word_len= 7;

ERROR HY000: Variable 'ft_max_word_len' is a read only variable

#

SHOW VARIABLES like 'ft_min_word_len';

Variable_name	Value

ft_min_word_len	4

SELECT @@session.ft_min_word_len;

ERROR HY000: Variable 'ft_min_word_len' is a GLOBAL variable

SELECT @@global.ft_min_word_len;

@@global.ft_min_word_len

4

SET @@session.ft_min_word_len= 7;

ERROR HY000: Variable 'ft_min_word_len' is a read only variable

SET @@global.ft_min_word_len= 7;

ERROR HY000: Variable 'ft_min_word_len' is a read only variable

#

SHOW VARIABLES like 'ft_query_expansion_limit';

Variable_name	Value

ft_query_expansion_limit	20

SELECT @@session.ft_query_expansion_limit;

ERROR HY000: Variable 'ft_query_expansion_limit' is a GLOBAL variable

SELECT @@global.ft_query_expansion_limit;

@@global.ft_query_expansion_limit

20

SET @@session.ft_query_expansion_limit= 7;

ERROR HY000: Variable 'ft_query_expansion_limit' is a read only variable

SET @@global.ft_query_expansion_limit= 7;

ERROR HY000: Variable 'ft_query_expansion_limit' is a read only variable

#

SHOW VARIABLES like 'ft_stopword_file';

Variable_name	Value

ft_stopword_file	(built-in)

SELECT @@session.ft_stopword_file;

ERROR HY000: Variable 'ft_stopword_file' is a GLOBAL variable

SELECT @@global.ft_stopword_file;

@@global.ft_stopword_file

(built-in)

SET @@session.ft_stopword_file= 'x';

ERROR HY000: Variable 'ft_stopword_file' is a read only variable

SET @@global.ft_stopword_file= 'x';

ERROR HY000: Variable 'ft_stopword_file' is a read only variable

#

SHOW VARIABLES like 'back_log';

Variable_name	Value

back_log	50

SELECT @@session.back_log;

ERROR HY000: Variable 'back_log' is a GLOBAL variable

SELECT @@global.back_log;

@@global.back_log

50

SET @@session.back_log= 7;

ERROR HY000: Variable 'back_log' is a read only variable

SET @@global.back_log= 7;

ERROR HY000: Variable 'back_log' is a read only variable

#

SHOW VARIABLES like 'large_files_support';

Variable_name	Value

large_files_support	#

SELECT @@session.large_files_support;

ERROR HY000: Variable 'large_files_support' is a GLOBAL variable

SELECT @@global.large_files_support;

@@global.large_files_support

#

SET @@session.large_files_support= true;

ERROR HY000: Variable 'large_files_support' is a read only variable

SET @@global.large_files_support= true;

ERROR HY000: Variable 'large_files_support' is a read only variable

#

SHOW VARIABLES like 'character_sets_dir';

Variable_name	Value

character_sets_dir	#

SELECT @@session.character_sets_dir;

ERROR HY000: Variable 'character_sets_dir' is a GLOBAL variable

SELECT @@global.character_sets_dir;

@@global.character_sets_dir

#

SET @@session.character_sets_dir= 'x';

ERROR HY000: Variable 'character_sets_dir' is a read only variable

SET @@global.character_sets_dir= 'x';

ERROR HY000: Variable 'character_sets_dir' is a read only variable

#

SHOW VARIABLES like 'init_file';

Variable_name	Value

init_file	#

SELECT @@session.init_file;

ERROR HY000: Variable 'init_file' is a GLOBAL variable

SELECT @@global.init_file;

@@global.init_file

#

SET @@session.init_file= 'x';

ERROR HY000: Variable 'init_file' is a read only variable

SET @@global.init_file= 'x';

ERROR HY000: Variable 'init_file' is a read only variable

#

SHOW VARIABLES like 'language';

Variable_name	Value

language	#

SELECT @@session.language;

ERROR HY000: Variable 'language' is a GLOBAL variable

SELECT @@global.language;

@@global.language

#

SET @@session.language= 'x';

ERROR HY000: Variable 'language' is a read only variable

SET @@global.language= 'x';

ERROR HY000: Variable 'language' is a read only variable

#

SHOW VARIABLES like 'large_page_size';

Variable_name	Value

large_page_size	#

SELECT @@session.large_page_size;

ERROR HY000: Variable 'large_page_size' is a GLOBAL variable

SELECT @@global.large_page_size;

@@global.large_page_size

#

SET @@session.large_page_size= 7;

ERROR HY000: Variable 'large_page_size' is a read only variable

SET @@global.large_page_size= 7;

ERROR HY000: Variable 'large_page_size' is a read only variable

#

SHOW VARIABLES like 'large_pages';

Variable_name	Value

large_pages	#

SELECT @@session.large_pages;

ERROR HY000: Variable 'large_pages' is a GLOBAL variable

SELECT @@global.large_pages;

@@global.large_pages

#

SET @@session.large_pages= true;

ERROR HY000: Variable 'large_pages' is a read only variable

SET @@global.large_pages= true;

ERROR HY000: Variable 'large_pages' is a read only variable

#

SHOW VARIABLES like 'log_bin';

Variable_name	Value

log_bin	OFF

SELECT @@session.log_bin;

ERROR HY000: Variable 'log_bin' is a GLOBAL variable

SELECT @@global.log_bin;

@@global.log_bin

0

SET @@session.log_bin= true;

ERROR HY000: Variable 'log_bin' is a read only variable

SET @@global.log_bin= true;

ERROR HY000: Variable 'log_bin' is a read only variable

#

SHOW VARIABLES like 'log_error';

Variable_name	Value

log_error	#

SELECT @@session.log_error;

ERROR HY000: Variable 'log_error' is a GLOBAL variable

SELECT @@global.log_error;

@@global.log_error

#

SET @@session.log_error= 'x';

ERROR HY000: Variable 'log_error' is a read only variable

SET @@global.log_error= 'x';

ERROR HY000: Variable 'log_error' is a read only variable

#

SHOW VARIABLES like 'lower_case_file_system';

Variable_name	Value

lower_case_file_system	#

SELECT @@session.lower_case_file_system;

ERROR HY000: Variable 'lower_case_file_system' is a GLOBAL variable

SELECT @@global.lower_case_file_system;

@@global.lower_case_file_system

#

SET @@session.lower_case_file_system= true;

ERROR HY000: Variable 'lower_case_file_system' is a read only variable

SET @@global.lower_case_file_system= true;

ERROR HY000: Variable 'lower_case_file_system' is a read only variable

#

SHOW VARIABLES like 'lower_case_table_names';

Variable_name	Value

lower_case_table_names	#

SELECT @@session.lower_case_table_names;

ERROR HY000: Variable 'lower_case_table_names' is a GLOBAL variable

SELECT @@global.lower_case_table_names;

@@global.lower_case_table_names

#

SET @@session.lower_case_table_names= 7;

ERROR HY000: Variable 'lower_case_table_names' is a read only variable

SET @@global.lower_case_table_names= 7;

ERROR HY000: Variable 'lower_case_table_names' is a read only variable

#

SHOW VARIABLES like 'myisam_recover_options';

Variable_name	Value

myisam_recover_options	OFF

SELECT @@session.myisam_recover_options;

ERROR HY000: Variable 'myisam_recover_options' is a GLOBAL variable

SELECT @@global.myisam_recover_options;

@@global.myisam_recover_options

OFF

SET @@session.myisam_recover_options= 'x';

ERROR HY000: Variable 'myisam_recover_options' is a read only variable

SET @@global.myisam_recover_options= 'x';

ERROR HY000: Variable 'myisam_recover_options' is a read only variable

#

SHOW VARIABLES like 'open_files_limit';

Variable_name	Value

open_files_limit	#

SELECT @@session.open_files_limit;

ERROR HY000: Variable 'open_files_limit' is a GLOBAL variable

SELECT @@global.open_files_limit;

@@global.open_files_limit

#

SET @@session.open_files_limit= 7;

ERROR HY000: Variable 'open_files_limit' is a read only variable

SET @@global.open_files_limit= 7;

ERROR HY000: Variable 'open_files_limit' is a read only variable

#

SHOW VARIABLES like 'pid_file';

Variable_name	Value

pid_file	#

SELECT @@session.pid_file;

ERROR HY000: Variable 'pid_file' is a GLOBAL variable

SELECT @@global.pid_file;

@@global.pid_file

#

SET @@session.pid_file= 'x';

ERROR HY000: Variable 'pid_file' is a read only variable

SET @@global.pid_file= 'x';

ERROR HY000: Variable 'pid_file' is a read only variable

#

SHOW VARIABLES like 'plugin_dir';

Variable_name	Value

plugin_dir	#

SELECT @@session.plugin_dir;

ERROR HY000: Variable 'plugin_dir' is a GLOBAL variable

SELECT @@global.plugin_dir;

@@global.plugin_dir

#

SET @@session.plugin_dir= 'x';

ERROR HY000: Variable 'plugin_dir' is a read only variable

SET @@global.plugin_dir= 'x';

ERROR HY000: Variable 'plugin_dir' is a read only variable

#

SHOW VARIABLES like 'port';

Variable_name	Value

port	#

SELECT @@session.port;

ERROR HY000: Variable 'port' is a GLOBAL variable

SELECT @@global.port;

@@global.port

#

SET @@session.port= 7;

ERROR HY000: Variable 'port' is a read only variable

SET @@global.port= 7;

ERROR HY000: Variable 'port' is a read only variable

#

SHOW VARIABLES like 'protocol_version';

Variable_name	Value

protocol_version	10

SELECT @@session.protocol_version;

ERROR HY000: Variable 'protocol_version' is a GLOBAL variable

SELECT @@global.protocol_version;

@@global.protocol_version

10

SET @@session.protocol_version= 7;

ERROR HY000: Variable 'protocol_version' is a read only variable

SET @@global.protocol_version= 7;

ERROR HY000: Variable 'protocol_version' is a read only variable

#

SHOW VARIABLES like 'skip_external_locking';

Variable_name	Value

skip_external_locking	ON

SELECT @@session.skip_external_locking;

ERROR HY000: Variable 'skip_external_locking' is a GLOBAL variable

SELECT @@global.skip_external_locking;

@@global.skip_external_locking

1

SET @@session.skip_external_locking= true;

ERROR HY000: Variable 'skip_external_locking' is a read only variable

SET @@global.skip_external_locking= true;

ERROR HY000: Variable 'skip_external_locking' is a read only variable

#

SHOW VARIABLES like 'skip_networking';

Variable_name	Value

skip_networking	OFF

SELECT @@session.skip_networking;

ERROR HY000: Variable 'skip_networking' is a GLOBAL variable

SELECT @@global.skip_networking;

@@global.skip_networking

0

SET @@session.skip_networking= true;

ERROR HY000: Variable 'skip_networking' is a read only variable

SET @@global.skip_networking= true;

ERROR HY000: Variable 'skip_networking' is a read only variable

#

SHOW VARIABLES like 'skip_show_database';

Variable_name	Value

skip_show_database	OFF

SELECT @@session.skip_show_database;

ERROR HY000: Variable 'skip_show_database' is a GLOBAL variable

SELECT @@global.skip_show_database;

@@global.skip_show_database

0

SET @@session.skip_show_database= true;

ERROR HY000: Variable 'skip_show_database' is a read only variable

SET @@global.skip_show_database= true;

ERROR HY000: Variable 'skip_show_database' is a read only variable

#

SHOW VARIABLES like 'socket';

Variable_name	Value

socket	#

SELECT @@session.socket;

ERROR HY000: Variable 'socket' is a GLOBAL variable

SELECT @@global.socket;

@@global.socket

#

SET @@session.socket= 'x';

ERROR HY000: Variable 'socket' is a read only variable

SET @@global.socket= 'x';

ERROR HY000: Variable 'socket' is a read only variable

#

SHOW VARIABLES like 'thread_stack';

Variable_name	Value

thread_stack	#

SELECT @@session.thread_stack;

ERROR HY000: Variable 'thread_stack' is a GLOBAL variable

SELECT @@global.thread_stack;

@@global.thread_stack

#

SET @@session.thread_stack= 7;

ERROR HY000: Variable 'thread_stack' is a read only variable

SET @@global.thread_stack= 7;

ERROR HY000: Variable 'thread_stack' is a read only variable

mysql-test/t/variables-notembedded.test

+80 −0
Original line number Diff line number Diff line
@@ -28,3 +28,83 @@ set global slave_net_timeout=default; 
# sql_slave_skip_counter is write-only, so we can't save previous

# value and restore it here.  That's ok, because it's normally 0.

set global sql_slave_skip_counter= 0;



#

# Bug#28234 - global/session scope - documentation vs implementation

#

--echo

#

# Additional variables fixed from sql_repl.cc.

#

--echo #

SHOW VARIABLES like 'log_slave_updates';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.log_slave_updates;

SELECT @@global.log_slave_updates;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.log_slave_updates= true;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.log_slave_updates= true;

#

--echo #

SHOW VARIABLES like 'relay_log';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.relay_log;

SELECT @@global.relay_log;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.relay_log= 'x';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.relay_log= 'x';

#

--echo #

SHOW VARIABLES like 'relay_log_index';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.relay_log_index;

SELECT @@global.relay_log_index;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.relay_log_index= 'x';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.relay_log_index= 'x';

#

--echo #

SHOW VARIABLES like 'relay_log_info_file';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.relay_log_info_file;

SELECT @@global.relay_log_info_file;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.relay_log_info_file= 'x';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.relay_log_info_file= 'x';

#

--echo #

SHOW VARIABLES like 'relay_log_space_limit';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.relay_log_space_limit;

SELECT @@global.relay_log_space_limit;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.relay_log_space_limit= 7;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.relay_log_space_limit= 7;

#

--echo #

--replace_column 2 #

SHOW VARIABLES like 'slave_load_tmpdir';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.slave_load_tmpdir;

--replace_column 1 #

SELECT @@global.slave_load_tmpdir;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.slave_load_tmpdir= 'x';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.slave_load_tmpdir= 'x';

#

--echo #

SHOW VARIABLES like 'slave_skip_errors';

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SELECT @@session.slave_skip_errors;

SELECT @@global.slave_skip_errors;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@session.slave_skip_errors= 7;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR

SET @@global.slave_skip_errors= 7;

#

mysql-test/t/variables.test

+296 −0

File changed.

Preview size limit exceeded, changes collapsed.

sql/item_func.cc

+10 −0
Original line number Diff line number Diff line
@@ -4855,6 +4855,7 @@ void Item_func_get_system_var::fix_length_and_dec() 
      max_length= MAX_BLOB_WIDTH;

      decimals=NOT_FIXED_DEC;

      break;

    case SHOW_BOOL:

    case SHOW_MY_BOOL:

      unsigned_flag= FALSE;

      max_length= 1;
@@ -4882,6 +4883,7 @@ enum Item_result Item_func_get_system_var::result_type() const 
{

  switch (var->show_type())

  {

    case SHOW_BOOL:

    case SHOW_MY_BOOL:

    case SHOW_INT:

    case SHOW_LONG:
@@ -4904,6 +4906,7 @@ enum_field_types Item_func_get_system_var::field_type() const 
{

  switch (var->show_type())

  {

    case SHOW_BOOL:

    case SHOW_MY_BOOL:

    case SHOW_INT:

    case SHOW_LONG:
@@ -4922,6 +4925,10 @@ enum_field_types Item_func_get_system_var::field_type() const 
}





/*

  Uses var, var_type, component, cache_present, used_query_id, thd,

  cached_llval, null_value, cached_null_value

*/

#define get_sys_var_safe(type) \

do { \

  type value; \
@@ -4975,6 +4982,7 @@ longlong Item_func_get_system_var::val_int() 
    case SHOW_LONG:     get_sys_var_safe (ulong);

    case SHOW_LONGLONG: get_sys_var_safe (longlong);

    case SHOW_HA_ROWS:  get_sys_var_safe (ha_rows);

    case SHOW_BOOL:     get_sys_var_safe (bool);

    case SHOW_MY_BOOL:  get_sys_var_safe (my_bool);

    case SHOW_DOUBLE:

      {
@@ -5072,6 +5080,7 @@ String* Item_func_get_system_var::val_str(String* str) 
    case SHOW_LONG:

    case SHOW_LONGLONG:

    case SHOW_HA_ROWS:

    case SHOW_BOOL:

    case SHOW_MY_BOOL:

      str->set (val_int(), collation.collation);

      break;
@@ -5164,6 +5173,7 @@ double Item_func_get_system_var::val_real() 
    case SHOW_LONG:

    case SHOW_LONGLONG:

    case SHOW_HA_ROWS:

    case SHOW_BOOL:

    case SHOW_MY_BOOL:

        cached_dval= (double) val_int();

        cache_present|= GET_SYS_VAR_CACHE_DOUBLE;