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Check of temporary tables hiding for query fetched from QC (BUG#6084)

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bell@sanja.is.com.ua 2004-10-21 23:56:12 +03:00
parent b32ffec8fd
commit ded12c828d
4 changed files with 59 additions and 1 deletions
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13
mysql-test/r/query_cache.result
View File

@ -704,4 +704,17 @@ Qcache_queries_in_cache 1
unlock table;
drop table t1,t2;
set query_cache_wlock_invalidate=default;
CREATE TABLE t1 (id INT PRIMARY KEY);
insert into t1 values (1),(2),(3);
select * from t1;
id
1
2
3
create temporary table t1 (a int not null auto_increment
primary key);
select * from t1;
a
drop table t1;
drop table t1;
set GLOBAL query_cache_size=0;

12
mysql-test/t/query_cache.test
View File

@ -521,4 +521,16 @@ unlock table;
drop table t1,t2;
set query_cache_wlock_invalidate=default;
#
# hiding real table stored in query cache by temporary table
#
CREATE TABLE t1 (id INT PRIMARY KEY);
insert into t1 values (1),(2),(3);
select * from t1;
create temporary table t1 (a int not null auto_increment
primary key);
select * from t1;
drop table t1;
drop table t1;
set GLOBAL query_cache_size=0;

32
sql/sql_cache.cc
View File

@ -971,9 +971,38 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length)
for (; block_table != block_table_end; block_table++)
{
TABLE_LIST table_list;
bzero((char*) &table_list,sizeof(table_list));
TABLE *tmptable;
Query_cache_table *table = block_table->parent;
/*
Check that we have not temporary tables with same names of tables
of this query. If we have such tables, we will not send data from
query cache, because temporary tables hide real tables by which
query in query cache was made.
*/
for (tmptable= thd->temporary_tables; tmptable ; tmptable= tmptable->next)
{
if (tmptable->key_length - 8 == table->key_len() &&
!memcmp(tmptable->table_cache_key, table->data(),
table->key_len()))
{
DBUG_PRINT("qcache",
("Temporary table detected: '%s.%s'",
table_list.db, table_list.alias));
STRUCT_UNLOCK(&structure_guard_mutex);
/*
We should not store result of this query because it contain
temporary tables => assign following wariable to make check
faster.
*/
thd->safe_to_cache_query=0;
BLOCK_UNLOCK_RD(query_block);
DBUG_RETURN(-1);
}
}
bzero((char*) &table_list,sizeof(table_list));
table_list.db = table->db();
table_list.alias= table_list.real_name= table->table();
if (check_table_access(thd,SELECT_ACL,&table_list,1))
@ -2066,6 +2095,7 @@ Query_cache::insert_table(uint key_len, char *key,
}
char *db = header->db();
header->table(db + db_length + 1);
header->key_len(key_len);
}
Query_cache_block_table *list_root = table_block->table(0);

3
sql/sql_cache.h
View File

@ -144,10 +144,13 @@ struct Query_cache_query
struct Query_cache_table
{
char *tbl;
uint32 key_length;
inline char *db() { return (char *) data(); }
inline char *table() { return tbl; }
inline void table(char *table) { tbl = table; }
inline uint32 key_len() { return key_length; }
inline void key_len(uint32 len) { key_length= len; }
inline gptr data()
{
return (gptr)(((byte*)this)+