maria-developers team mailing list archive

[Igor Babaev <igor@xxxxxxxxxxxx>]

On 10/22/2012 12:53 AM, Timour Katchaounov wrote:
> Igor,
> 
> Great, the patch indeed fixes the bug both on 5.3 and 5.5, however the
> reduced test case I produced still takes 21 MB, and I was not successful
> in reducing it to a size that can be added to the regression test suite.
> I already spent too much in reducing the test case. Would you agree that
> I push your patch without a test case?

I think you still have to add the test case case (in a separate file)
that is run with the --big option.

Regards,
Igor.

> 
> Timour
> 
> 
> On 20.10.2012 08:56, Igor Babaev wrote:
>> On 10/19/2012 12:43 PM, Timour Katchaounov wrote:
>>> Hi Igor,
>>>
>>> Could you please look at this bug
>>> https://mariadb.atlassian.net/browse/MDEV-3801,
>>> and read my last comment. The bug may be (just a guess ATM) related to
>>> index
>>> creation on the temporary table created for the derived table. Since
>>> this is your
>>> code, I'd like you to tell me if you have seen anything similar before,
>>> or if
>>> you have any hints.
>>>
>>> If not, I will continue with the bug and will trace the cause for the
>>> wrong key information.
>>>
>>> Thanks,
>>> Timour
>>
>> Timour,
>>
>> The following patch fixes this problem
>>
>> Regards,
>> Igor.
>>
>> === modified file 'sql/sql_select.cc'
>> --- sql/sql_select.cc   2012-10-10 05:21:22 +0000
>> +++ sql/sql_select.cc   2012-10-20 05:49:13 +0000
>> @@ -8981,7 +8981,7 @@ void JOIN::drop_unused_derived_keys()
>>     JOIN_TAB *tab;
>>     for (tab= first_linear_tab(this, WITHOUT_CONST_TABLES);
>>          tab;
>> -       tab= next_linear_tab(this, tab, WITHOUT_BUSH_ROOTS))
>> +       tab= next_linear_tab(this, tab, WITH_BUSH_ROOTS))
>>     {
>>
>>       TABLE *table=tab->table;
>>
>> MariaDB [test]> set @@tmp_table_size=16384;
>> ERROR 2006 (HY000): MySQL server has gone away
>> No connection. Trying to reconnect...
>> Connection id:    1
>> Current database: test
>>
>> Query OK, 0 rows affected (5.48 sec)
>>
>> MariaDB [test]> set @@tmp_table_size=16384;
>> Query OK, 0 rows affected (0.00 sec)
>>
>> MariaDB [test]> EXPLAIN SELECT t1.deal_id FROM table_e AS t1 JOIN
>> table_d AS t10 ON (t1.deal_id = t10.deal_id) WHERE   t1.deal_id IN
>> (SELECT *    FROM (SELECT DISTINCT t1.deal_id          FROM table_e AS
>> t1               JOIN table_d AS t2 ON (t1.deal_id = t2.deal_id)
>>         JOIN table_c_s AS t3 ON (t2.deal_id = t3.deal_id) AND (t2.feid =
>> t3.feid)               JOIN table_f AS t4 ON t3.exchange = t4.exchange)
>> tU) limit 10;
>> +----+--------------+-------------+--------+-------------------------------------------+----------+---------+------------------------------+------+-----------------------+
>>
>> | id | select_type  | table       | type   | possible_keys
>>                 | key      | key_len | ref                          |
>> rows | Extra                 |
>> +----+--------------+-------------+--------+-------------------------------------------+----------+---------+------------------------------+------+-----------------------+
>>
>> |  1 | PRIMARY      | <subquery2> | ALL    | distinct_key
>>                 | NULL     | NULL    | NULL                         |
>> 8488 |                       |
>> |  1 | PRIMARY      | t1          | eq_ref | PRIMARY
>>                 | PRIMARY  | 4       | tU.deal_id                   |
>> 1 | Using index           |
>> |  1 | PRIMARY      | t10         | ref    | PRIMARY,full_id
>>                 | PRIMARY  | 4       | tU.deal_id                   |
>> 1 | Using index           |
>> |  2 | MATERIALIZED | <derived3>  | ALL    | NULL
>>                 | NULL     | NULL    | NULL                         |
>> 8488 |                       |
>> |  3 | DERIVED      | t4          | system | PRIMARY
>>                 | NULL     | NULL    | NULL                         |
>> 1 | Using temporary       |
>> |  3 | DERIVED      | t3          | ref    |
>> PRIMARY,feid,exchange,deal_feid,feid_date | exchange | 3       | const
>>                        | 8488 |                       |
>> |  3 | DERIVED      | t1          | eq_ref | PRIMARY
>>                 | PRIMARY  | 4       | test.t3.deal_id              |
>> 1 | Using index           |
>> |  3 | DERIVED      | t2          | eq_ref | PRIMARY,full_id
>>                 | PRIMARY  | 8       | test.t3.deal_id,test.t3.feid |
>> 1 | Using index; Distinct |
>> +----+--------------+-------------+--------+-------------------------------------------+----------+---------+------------------------------+------+-----------------------+
>>
>> 8 rows in set (4.22 sec)
>>
>> MariaDB [test]> SELECT t1.deal_id FROM table_e AS t1 JOIN table_d AS t10
>> ON (t1.deal_id = t10.deal_id) WHERE   t1.deal_id IN   (SELECT *    FROM
>> (SELECT DISTINCT t1.deal_id          FROM table_e AS t1
>> JOIN table_d AS t2 ON (t1.deal_id = t2.deal_id)               JOIN
>> table_c_s AS t3 ON (t2.deal_id = t3.deal_id) AND (t2.feid = t3.feid)
>>             JOIN table_f AS t4 ON t3.exchange = t4.exchange) tU) limit
>> 10;
>> +---------+
>> | deal_id |
>> +---------+
>> |      30 |
>> |      82 |
>> |      83 |
>> |     108 |
>> |     155 |
>> |     156 |
>> |     162 |
>> |     184 |
>> |     186 |
>> |     195 |
>> +---------+
>> 10 rows in set (10.62 sec)
>>