Guilhem,
Guilhem Bichot wrote:
> On Sat, Oct 13, 2007 at 08:24:04AM +0530, Sunny Bains wrote:
>> While investigating http://bugs.mysql.com/bug.php?id=31540, I noticed
>> that MySQL calls ha_innobase::get_auto_increment() with different
>> values for nb_desired_values within a multi-row insert.
>
> Could you please post here a simple SQL testcase which demonstrates
> the gap occuring?
>
This is running the new autoinc fix with autoinc_lock_mode = 1. Where
InnoDB allocates nb_reserved_values each time get_auto_increment()
is called via update_row(). Also for the example below to work, you
need to add the following line to ha_innobase::start_stmt():
/* Reset the AUTOINC statement level counter for multi-row INSERTs. */
trx->n_autoinc_rows = 0;
create table a (a int, val char(1)) engine=InnoDB;
create table b (
b int auto_increment primary key,
val char(1)) engine=InnoDB;
create trigger a_after_insert after
insert on a for each row insert into b
set val NEW.val;
insert into a values ( 123, 'a'), ( 123, 'b'), ( 123, 'c'),
(123, 'd'), (123, 'e'), (123, 'f'), (123, 'g');
mysql> select * from b;
+----+------+
| b | val |
+----+------+
| 1 | a |
| 2 | b |
| 4 | c |
| 6 | d |
| 8 | e |
| 10 | f |
| 12 | g |
+----+------+
The backtrace that I posted in the original message was taken while
running the above example.
Breakpoint 2, ha_innobase::get_auto_increment (this=0x8b78988, offset=1,
increment=1, nb_desired_values=1, first_value=0x8f1b9260,
nb_reserved_values=0x8f1b9258) at handler/ha_innodb.cc:7314
and so we reserve one value.
Subsequent calls have the following values:
Breakpoint 2, ha_innobase::get_auto_increment (this=0x8b78988, offset=1,
increment=1, nb_desired_values=2, first_value=0x8f1b9260,
nb_reserved_values=0x8f1b9258) at handler/ha_innodb.cc:7314
...
Breakpoint 2, ha_innobase::get_auto_increment (this=0x8b78988, offset=1,
increment=1, nb_desired_values=2, first_value=0x8f1b9260,
nb_reserved_values=0x8f1b9258) at handler/ha_innodb.cc:7314
...
and so we reserve two values and so on.
Will this do or are you asking for something else ?
Regards,
-sunny
