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Fix UNION

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New faster list iterators
Change list code to be simpler and faster
Optimize count(distinct)
New error messages for UNION
Make create_tmp_table more general to be usable by UNION
This commit is contained in:
monty@tik.mysql.fi
2001-08-02 06:29:50 +03:00
parent 423f2851c5
commit b13d453d50
57 changed files with 798 additions and 472 deletions
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130
sql/sql_parse.cc
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@ -47,7 +47,8 @@ static void mysql_init_query(THD *thd);
static void remove_escape(char *name);
static void refresh_status(void);
static bool append_file_to_dir(char **filename_ptr, char *table_name);
static int link_in_large_list_and_check_acl(THD *thd,LEX *lex,SQL_LIST *tables);
static int create_total_list_and_check_acl(THD *thd, LEX *lex,
TABLE_LIST **result);
const char *any_db="*any*"; // Special symbol for check_access
@ -1737,10 +1738,10 @@ mysql_execute_command(void)
}
case SQLCOM_UNION_SELECT:
{
SQL_LIST *total=(SQL_LIST *) thd->calloc(sizeof(SQL_LIST));
TABLE_LIST *total;
if (select_lex->options & SELECT_DESCRIBE)
lex->exchange=0;
if ((res = link_in_large_list_and_check_acl(thd,lex,total)) == -1)
if ((res = create_total_list_and_check_acl(thd,lex,&total)) == -1)
{
res=0;
break;
@ -1753,31 +1754,31 @@ mysql_execute_command(void)
res=0;
break;
}
if (!(res=open_and_lock_tables(thd,(TABLE_LIST *)total->first)))
{
/* Fix tables--to-be-unioned-from list to point at opened tables */
for (SELECT_LEX *sl=&lex->select_lex;sl;sl=sl->next)
{
for (TABLE_LIST *cursor=(TABLE_LIST *)sl->table_list.first;cursor;cursor=cursor->next)
cursor->table= ((TABLE_LIST*) cursor->table)->table;
}
ha_rows save_it=thd->offset_limit; thd->offset_limit=0;
res=mysql_union(thd,lex, select_lex->select_number+1);
thd->offset_limit=save_it;
}
if (!(res=open_and_lock_tables(thd, total)))
{
/* Fix tables--to-be-unioned-from list to point at opened tables */
for (SELECT_LEX *sl=&lex->select_lex; sl; sl=sl->next)
{
for (TABLE_LIST *cursor= (TABLE_LIST *)sl->table_list.first;
cursor;
cursor=cursor->next)
cursor->table= ((TABLE_LIST*) cursor->table)->table;
}
res=mysql_union(thd,lex);
}
close_thread_tables(thd);
break;
}
case SQLCOM_DROP_TABLE:
{
if (check_table_access(thd,DROP_ACL,tables))
goto error; /* purecov: inspected */
if (end_active_trans(thd))
res= -1;
else
res = mysql_rm_table(thd,tables,lex->drop_if_exists);
}
break;
{
if (check_table_access(thd,DROP_ACL,tables))
goto error; /* purecov: inspected */
if (end_active_trans(thd))
res= -1;
else
res = mysql_rm_table(thd,tables,lex->drop_if_exists);
}
break;
case SQLCOM_DROP_INDEX:
if (!tables->db)
tables->db=thd->db;
@ -2901,53 +2902,66 @@ TABLE_LIST *add_table_to_list(Table_ident *table, LEX_STRING *alias,
DBUG_RETURN(ptr);
}
static int link_in_large_list_and_check_acl(THD *thd,LEX *lex,SQL_LIST *tables)
/*
** This is used for UNION to create a new table list of all used tables
** The table_list->table entry in all used tables are set to point
** to the entries in this list.
*/
static int create_total_list_and_check_acl(THD *thd, LEX *lex,
TABLE_LIST **result)
{
SELECT_LEX *sl; const char *current_db=thd->db ? thd->db : "";
TABLE_LIST *ptr;
for (sl=&lex->select_lex;sl;sl=sl->next)
SELECT_LEX *sl;
TABLE_LIST **new_table_list= result, *aux;
const char *current_db=thd->db ? thd->db : ""; // QQ; To be removed
*new_table_list=0; // end result list
for (sl=&lex->select_lex; sl; sl=sl->next)
{
if ((lex->sql_command == SQLCOM_UNION_SELECT) && (sl->order_list.first != (byte *)NULL) && (sl->next != (st_select_lex *)NULL))
if ((lex->sql_command == SQLCOM_UNION_SELECT) &&
sl->order_list.first && sl->next)
{
net_printf(&thd->net,ER_ILLEGAL_GRANT_FOR_TABLE); // correct error message will come here; only last SELECT can have ORDER BY
net_printf(&thd->net,ER_WRONG_USAGE,"UNION","ORDER BY");
return -1;
}
if (sl->table_list.first == (byte *)NULL) continue;
TABLE_LIST *cursor,*aux=(TABLE_LIST*) sl->table_list.first;
aux= (TABLE_LIST*) sl->table_list.first;
if (aux)
{
if (check_table_access(thd, lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL , aux))
return -1;
for (;aux;aux=aux->next)
TABLE_LIST *next;
if (check_table_access(thd,
lex->exchange ?
SELECT_ACL | FILE_ACL : SELECT_ACL , aux))
return -1;
for (; aux; aux=next)
{
if (!aux->db)
aux->db=(char *)current_db;
for (cursor=(TABLE_LIST *)tables->first;cursor;cursor=cursor->next)
if (!strcmp(cursor->db,aux->db) && (!strcmp(cursor->real_name,aux->real_name)))
break;
if (!cursor || !tables->first)
{
aux->lock_type= lex->lock_option;
if (!tables->next)
tables->next= (byte**) &tables->first;
if (!(ptr = (TABLE_LIST *) thd->calloc(sizeof(TABLE_LIST))))
return 1;
ptr->db= aux->db; ptr->real_name=aux->real_name;
ptr->name=aux->name; ptr->lock_type=aux->lock_type;
ptr->updating=aux->updating;
ptr->use_index=aux->use_index;
ptr->ignore_index=aux->use_index;
aux->table=(TABLE *)ptr;
link_in_list(tables,(byte*)ptr,(byte**) &ptr->next);
}
else
aux->table=(TABLE *)cursor;
TABLE_LIST *cursor;
next= aux->next;
if (!aux->db)
aux->db=(char *)current_db; // QQ; To be removed
for (cursor= *result; cursor; cursor=cursor->next)
if (!strcmp(cursor->db,aux->db) &&
(!strcmp(cursor->real_name,aux->real_name)))
break;
if (!cursor)
{
/* Add not used table to the total table list */
aux->lock_type= lex->lock_option;
if (!(cursor = (TABLE_LIST *) thd->memdup((byte*) aux,
sizeof(*aux))))
return 1;
*new_table_list= cursor;
new_table_list= &cursor->next;
*new_table_list=0; // end result list
}
aux->table=(TABLE *) cursor;
}
}
}
return (tables->first) ? 0 : 1;
return 0;
}
void add_join_on(TABLE_LIST *b,Item *expr)
{
if (!b->on_expr)