Commit 5424cf19 authored by svoj@mysql.com/april.(none)'s avatar svoj@mysql.com/april.(none)

Merge mysql.com:/home/svoj/devel/bk/mysql-4.1-engines

into  mysql.com:/home/svoj/devel/mysql/BUG21310/mysql-4.1-engines
parents f3f5eb5c 5ad90356
......@@ -944,3 +944,19 @@ 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;
......@@ -890,4 +890,23 @@ 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;
# End of 4.1 tests
......@@ -528,7 +528,7 @@ int mysql_lock_have_duplicate(THD *thd, TABLE *table, TABLE_LIST *tables)
for (; tables; tables= tables->next)
{
table2= tables->table;
if (table2->tmp_table == TMP_TABLE)
if (table2->tmp_table == TMP_TABLE || table == table2)
continue;
/* All tables in list must be in lock. */
......
......@@ -23,8 +23,6 @@
#include "mysql_priv.h"
#include "sql_select.h"
static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields);
/* Return 0 if row hasn't changed */
static bool compare_record(TABLE *table, ulong query_id)
......@@ -846,27 +844,69 @@ 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
fields Fields that are updated
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= all_tables; table_ref; table_ref=table_ref->next)
{
TABLE *table=table_ref->table;
if ((tables_to_update & table->map) &&
mysql_lock_have_duplicate(thd, table, 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.
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 *all_tables, List<Item> *fields)
{
TABLE *table= join_tab->table;
/* First check if a table is not joined to itself. */
if (mysql_lock_have_duplicate(thd, table, all_tables))
return 0;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return 1; // At most one matching row
case JT_REF:
return !check_if_key_used(table, join_tab->ref.key, *fields);
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !check_if_key_used(table, join_tab->quick->index,
*fields);
/* If scanning in clustered key */
if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->primary_key < MAX_KEY)
return !check_if_key_used(table, table->primary_key, *fields);
return 1;
default:
break; // Avoid compler warning
}
DBUG_RETURN(thd->is_fatal_error != 0);
return 0;
}
......@@ -905,7 +945,7 @@ 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, &temp_fields))
if (safe_update_on_fly(thd, join->join_tab, all_tables, &temp_fields))
{
table_to_update= main_table; // Update table on the fly
continue;
......@@ -951,59 +991,6 @@ 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
fields Fields that are updated
NOTES
We can update the first table in join on the fly if we know that
a row in this tabel will never be read twice. This is true under
the folloing 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.
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, List<Item> *fields)
{
TABLE *table= join_tab->table;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return 1; // At most one matching row
case JT_REF:
return !check_if_key_used(table, join_tab->ref.key, *fields);
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !check_if_key_used(table, join_tab->quick->index,
*fields);
/* If scanning in clustered key */
if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->primary_key < MAX_KEY)
return !check_if_key_used(table, table->primary_key, *fields);
return 1;
default:
break; // Avoid compler warning
}
return 0;
}
multi_update::~multi_update()
{
......
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