Commit 9d106f7a authored by svoj@june.mysql.com's avatar svoj@june.mysql.com

Merge mysql.com:/home/svoj/devel/mysql/BUG21310/mysql-5.0-engines

into  mysql.com:/home/svoj/devel/mysql/BUG21310/mysql-5.1-engines
parents c8ed519a a86ee0c1
......@@ -1603,6 +1603,22 @@ select * from t1;
a
42
drop table t1;
CREATE TABLE t1(a VARCHAR(16));
INSERT INTO t1 VALUES('aaaaaaaa'),(NULL);
UPDATE t1 AS ta1, t1 AS ta2 SET ta1.a='aaaaaaaaaaaaaaaa';
SELECT * FROM t1;
a
aaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaa
DROP TABLE t1;
CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES(1),(2);
UPDATE t1,t1 AS t2 SET t1.a=t1.a+2 WHERE t1.a=t2.a-1;
SELECT * FROM t1 ORDER BY a;
a
2
3
DROP TABLE t1;
End of 4.1 tests
create table t1 (c1 int) engine=myisam pack_keys=0;
create table t2 (c1 int) engine=myisam pack_keys=1;
......
......@@ -977,6 +977,24 @@ connection default;
select * from t1;
drop table t1;
#
# BUG#21310 - Trees in SQL causing a "crashed" table with MyISAM storage
# engine
#
# A simplified test case that reflect crashed table issue.
CREATE TABLE t1(a VARCHAR(16));
INSERT INTO t1 VALUES('aaaaaaaa'),(NULL);
UPDATE t1 AS ta1, t1 AS ta2 SET ta1.a='aaaaaaaaaaaaaaaa';
SELECT * FROM t1;
DROP TABLE t1;
# A test case that reflect wrong result set.
CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES(1),(2);
UPDATE t1,t1 AS t2 SET t1.a=t1.a+2 WHERE t1.a=t2.a-1;
SELECT * FROM t1 ORDER BY a;
DROP TABLE t1;
--echo End of 4.1 tests
#
......
......@@ -24,8 +24,6 @@
#include "sp_head.h"
#include "sql_trigger.h"
static bool safe_update_on_fly(JOIN_TAB *join_tab);
/* Return 0 if row hasn't changed */
static bool compare_record(TABLE *table)
......@@ -1160,27 +1158,71 @@ int multi_update::prepare(List<Item> &not_used_values,
for (i=0 ; i < table_count ; i++)
set_if_bigger(max_fields, fields_for_table[i]->elements);
copy_field= new Copy_field[max_fields];
DBUG_RETURN(thd->is_fatal_error != 0);
}
/*
Mark all copies of tables that are updates to ensure that
init_read_record() will not try to enable a cache on them
The problem is that for queries like
/*
Check if table is safe to update on fly
UPDATE t1, t1 AS t2 SET t1.b=t2.c WHERE t1.a=t2.a;
SYNOPSIS
safe_update_on_fly()
thd Thread handler
join_tab How table is used in join
all_tables List of tables
the row buffer may contain things that doesn't match what is on disk
which will cause an error when reading a row.
(This issue is mostly relevent for MyISAM tables)
*/
for (table_ref= leaves; table_ref; table_ref= table_ref->next_leaf)
{
TABLE *table=table_ref->table;
if ((tables_to_update & table->map) &&
unique_table(thd, table_ref, update_tables))
table->no_cache= 1; // Disable row cache
NOTES
We can update the first table in join on the fly if we know that
a row in this table will never be read twice. This is true under
the following conditions:
- We are doing a table scan and the data is in a separate file (MyISAM) or
if we don't update a clustered key.
- We are doing a range scan and we don't update the scan key or
the primary key for a clustered table handler.
- Table is not joined to itself.
This function gets information about fields to be updated from
the TABLE::write_set bitmap.
WARNING
This code is a bit dependent of how make_join_readinfo() works.
RETURN
0 Not safe to update
1 Safe to update
*/
static bool safe_update_on_fly(THD *thd, JOIN_TAB *join_tab,
TABLE_LIST *table_ref, TABLE_LIST *all_tables)
{
TABLE *table= join_tab->table;
if (unique_table(thd, table_ref, all_tables))
return 0;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return TRUE; // At most one matching row
case JT_REF:
case JT_REF_OR_NULL:
return !is_key_used(table, join_tab->ref.key, table->write_set);
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !join_tab->quick->is_keys_used(table->write_set);
/* If scanning in clustered key */
if ((table->file->ha_table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->s->primary_key < MAX_KEY)
return !is_key_used(table, table->s->primary_key, table->write_set);
return TRUE;
default:
break; // Avoid compler warning
}
DBUG_RETURN(thd->is_fatal_error != 0);
return FALSE;
}
......@@ -1220,7 +1262,7 @@ multi_update::initialize_tables(JOIN *join)
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
if (table == main_table) // First table in join
{
if (safe_update_on_fly(join->join_tab))
if (safe_update_on_fly(thd, join->join_tab, table_ref, all_tables))
{
table_to_update= main_table; // Update table on the fly
continue;
......@@ -1272,61 +1314,6 @@ multi_update::initialize_tables(JOIN *join)
DBUG_RETURN(0);
}
/*
Check if table is safe to update on fly
SYNOPSIS
safe_update_on_fly
join_tab How table is used in join
NOTES
We can update the first table in join on the fly if we know that
a row in this table will never be read twice. This is true under
the following conditions:
- We are doing a table scan and the data is in a separate file (MyISAM) or
if we don't update a clustered key.
- We are doing a range scan and we don't update the scan key or
the primary key for a clustered table handler.
This function gets information about fields to be updated from
the TABLE::write_set bitmap.
WARNING
This code is a bit dependent of how make_join_readinfo() works.
RETURN
0 Not safe to update
1 Safe to update
*/
static bool safe_update_on_fly(JOIN_TAB *join_tab)
{
TABLE *table= join_tab->table;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return TRUE; // At most one matching row
case JT_REF:
case JT_REF_OR_NULL:
return !is_key_used(table, join_tab->ref.key, table->write_set);
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !join_tab->quick->is_keys_used(table->write_set);
/* If scanning in clustered key */
if ((table->file->ha_table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->s->primary_key < MAX_KEY)
return !is_key_used(table, table->s->primary_key, table->write_set);
return TRUE;
default:
break; // Avoid compler warning
}
return FALSE;
}
multi_update::~multi_update()
{
......
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