90
91
static TYPELIB known_extensions= {0,"known_exts", NULL, NULL};
91
92
uint known_extensions_id= 0;
95
Database name that hold most of mysqld system tables.
96
Current code assumes that, there exists only some
97
specific "database name" designated as system database.
99
const char* mysqld_system_database= "mysql";
101
// System tables that belong to mysqld_system_database.
102
st_system_tablename mysqld_system_tables[]= {
103
{mysqld_system_database, "db"},
104
{mysqld_system_database, "user"},
105
{mysqld_system_database, "host"},
106
{mysqld_system_database, "func"},
107
{mysqld_system_database, "proc"},
108
{mysqld_system_database, "event"},
109
{mysqld_system_database, "plugin"},
110
{mysqld_system_database, "servers"},
111
{mysqld_system_database, "procs_priv"},
112
{mysqld_system_database, "tables_priv"},
113
{mysqld_system_database, "proxies_priv"},
114
{mysqld_system_database, "columns_priv"},
115
{mysqld_system_database, "time_zone"},
116
{mysqld_system_database, "time_zone_name"},
117
{mysqld_system_database, "time_zone_leap_second"},
118
{mysqld_system_database, "time_zone_transition"},
119
{mysqld_system_database, "time_zone_transition_type"},
120
{mysqld_system_database, "help_category"},
121
{mysqld_system_database, "help_keyword"},
122
{mysqld_system_database, "help_relation"},
123
{mysqld_system_database, "help_topic"},
124
{(const char *)NULL, (const char *)NULL} /* This must be at the end */
128
This static pointer holds list of system databases from SQL layer and
129
various SE's. The required memory is allocated once, and never freed.
131
static const char **known_system_databases= NULL;
132
static const char **ha_known_system_databases();
134
// Called for each SE to get SE specific system database.
135
static my_bool system_databases_handlerton(THD *unused, plugin_ref plugin,
138
// Called for each SE to check if given db.table_name is a system table.
139
static my_bool check_engine_system_table_handlerton(THD *unused,
144
Structure used by SE during check for system table.
145
This structure is passed to each SE handlerton and the status (OUT param)
148
struct st_sys_tbl_chk_params
150
const char *db; // IN param
151
const char *table_name; // IN param
152
bool is_sql_layer_system_table; // IN param
153
legacy_db_type db_type; // IN param
155
enum enum_sys_tbl_chk_status
157
// db.table_name is not a supported system table.
158
NOT_KNOWN_SYSTEM_TABLE,
160
db.table_name is a system table,
161
but may not be supported by SE.
165
db.table_name is a system table,
166
and is supported by SE.
168
SUPPORTED_SYSTEM_TABLE
169
}status; // OUT param
95
173
static plugin_ref ha_default_plugin(THD *thd)
3784
3874
DBUG_RETURN(FALSE);
3878
@brief Check if a given table is a system table.
3880
@details The primary purpose of introducing this function is to stop system
3881
tables to be created or being moved to undesired storage engines.
3883
@todo There is another function called is_system_table_name() used by
3884
get_table_category(), which is used to set TABLE_SHARE table_category.
3885
It checks only a subset of table name like proc, event and time*.
3886
We cannot use below function in get_table_category(),
3887
as that affects locking mechanism. If we need to
3888
unify these functions, we need to fix locking issues generated.
3890
@param hton Handlerton of new engine.
3891
@param db Database name.
3892
@param table_name Table name to be checked.
3894
@return Operation status
3895
@retval true If the table name is a valid system table
3896
or if its a valid user table.
3898
@retval false If the table name is a system table name
3899
and does not belong to engine specified
3902
bool ha_check_if_supported_system_table(handlerton *hton, const char *db,
3903
const char *table_name)
3905
DBUG_ENTER("ha_check_if_supported_system_table");
3906
st_sys_tbl_chk_params check_params;
3907
bool is_system_database= false;
3909
st_system_tablename *systab;
3911
// Check if we have a system database name in the command.
3912
DBUG_ASSERT(known_system_databases != NULL);
3913
names= known_system_databases;
3914
while (names && *names)
3916
if (strcmp(*names, db) == 0)
3918
/* Used to compare later, will be faster */
3919
check_params.db= *names;
3920
is_system_database= true;
3925
if (!is_system_database)
3926
DBUG_RETURN(true); // It's a user table name.
3928
// Check if this is SQL layer system tables.
3929
systab= mysqld_system_tables;
3930
check_params.is_sql_layer_system_table= false;
3931
while (systab && systab->db)
3933
if (systab->db == check_params.db &&
3934
strcmp(systab->tablename, table_name) == 0)
3936
check_params.is_sql_layer_system_table= true;
3942
// Check if this is a system table and if some engine supports it.
3943
check_params.status= check_params.is_sql_layer_system_table ?
3944
st_sys_tbl_chk_params::KNOWN_SYSTEM_TABLE :
3945
st_sys_tbl_chk_params::NOT_KNOWN_SYSTEM_TABLE;
3946
check_params.db_type= hton->db_type;
3947
check_params.table_name= table_name;
3948
plugin_foreach(NULL, check_engine_system_table_handlerton,
3949
MYSQL_STORAGE_ENGINE_PLUGIN, &check_params);
3951
// SE does not support this system table.
3952
if (check_params.status == st_sys_tbl_chk_params::KNOWN_SYSTEM_TABLE)
3955
// It's a system table or a valid user table.
3960
@brief Called for each SE to check if given db, tablename is a system table.
3962
@details The primary purpose of introducing this function is to stop system
3963
tables to be created or being moved to undesired storage engines.
3965
@param unused unused THD*
3966
@param plugin Points to specific SE.
3967
@param arg Is of type struct st_sys_tbl_chk_params.
3970
args->status Indicates OUT param,
3971
see struct st_sys_tbl_chk_params definition for more info.
3973
@return Operation status
3974
@retval true There was a match found.
3975
This will stop doing checks with other SE's.
3977
@retval false There was no match found.
3978
Other SE's will be checked to find a match.
3980
static my_bool check_engine_system_table_handlerton(THD *unused,
3984
st_sys_tbl_chk_params *check_params= (st_sys_tbl_chk_params*) arg;
3985
handlerton *hton= plugin_data(plugin, handlerton *);
3987
// Do we already know that the table is a system table?
3988
if (check_params->status == st_sys_tbl_chk_params::KNOWN_SYSTEM_TABLE)
3991
If this is the same SE specified in the command, we can
3992
simply ask the SE if it supports it stop the search regardless.
3994
if (hton->db_type == check_params->db_type)
3996
if (hton->is_supported_system_table &&
3997
hton->is_supported_system_table(check_params->db,
3998
check_params->table_name,
3999
check_params->is_sql_layer_system_table))
4000
check_params->status= st_sys_tbl_chk_params::SUPPORTED_SYSTEM_TABLE;
4004
If this is a different SE, there is no point in asking the SE
4005
since we already know it's a system table and we don't care
4006
if it is supported or not.
4012
We don't yet know if the table is a system table or not.
4013
We therefore must always ask the SE.
4015
if (hton->is_supported_system_table &&
4016
hton->is_supported_system_table(check_params->db,
4017
check_params->table_name,
4018
check_params->is_sql_layer_system_table))
4021
If this is the same SE specified in the command, we know it's a
4022
supported system table and can stop the search.
4024
if (hton->db_type == check_params->db_type)
4026
check_params->status= st_sys_tbl_chk_params::SUPPORTED_SYSTEM_TABLE;
4030
check_params->status= st_sys_tbl_chk_params::KNOWN_SYSTEM_TABLE;
4037
Prepare list of all known system database names
4038
current we just have 'mysql' as system database name.
4040
Later ndbcluster, innodb SE's can define some new database
4041
name which can store system tables specific to SE.
4043
const char** ha_known_system_databases(void)
4045
I_List<i_string> found_databases;
4046
const char **databases, **database;
4048
// Get mysqld system database name.
4049
found_databases.push_back(new i_string(mysqld_system_database));
4051
// Get system database names from every specific storage engine.
4052
plugin_foreach(NULL, system_databases_handlerton,
4053
MYSQL_STORAGE_ENGINE_PLUGIN, &found_databases);
4055
int element_count= 0;
4056
I_List_iterator<i_string> iter(found_databases);
4057
while (iter++) element_count++;
4058
databases= (const char **) my_once_alloc(sizeof(char *)*
4060
MYF(MY_WME | MY_FAE));
4061
DBUG_ASSERT(databases != NULL);
4063
database= databases;
4065
while ((tmp= found_databases.get()))
4067
*database++= tmp->ptr;
4070
*database= NULL; // Last element.
4076
@brief Fetch system database name specific to SE.
4078
@details This function is invoked by plugin_foreach() from
4079
ha_known_system_databases(), for each storage engine.
4081
static my_bool system_databases_handlerton(THD *unused, plugin_ref plugin,
4084
I_List<i_string> *found_databases= (I_List<i_string> *) arg;
4087
handlerton *hton= plugin_data(plugin, handlerton *);
4088
if (hton->system_database)
4090
db= hton->system_database();
4092
found_databases->push_back(new i_string(db));
3788
4099
void st_ha_check_opt::init()
added
removed
sql/handler.cc
