Bug #27946 Falcon delete takes long time

• Submitted: 19 Apr 2007 7:38
• Modified: 13 Nov 2007 8:22
• Reporter: Hakan Küçükyılmaz
• Status: Closed
• Category: MySQL Server: Falcon storage engine
• Severity: S3 (Non-critical)
• OS: Any
• CPU Architecture: Any

[19 Apr 2007 7:38] Hakan Küçükyılmaz

Description:
DELETE operation takes long time. I compared it with InnoDB.

InnoDB:
- Load 12:30 minutes
- Delete 27 seconds

Falcon:
- Load 12:50 minutes
- Delete 09:03 hours

How to repeat:
I used the stored procedure described in Bug#26055 to load the data:

delimiter //
set @@autocommit=0//
drop table tu//
drop procedure pu//
set @@sql_mode=traditional//
set names utf8//
create table tu (s1 varchar(10) character set utf8) engine=falcon//
create procedure pu () begin declare v1 int default 0; declare continue handler
for sqlexception begin end; while v1 <= 16777216 do if v1 mod 1000 = 0 then
select v1; commit; end if; set @v = concat('insert into tu values
(0x',hex(v1),')'); prepare stmt1 from @v; execute stmt1; set v1 = v1 + 1; end
while; end//
call pu()//

Restart mysqld.

mysql> show create table tu;
+-------+---------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                  |
+-------+---------------------------------------------------------------------------------------------------------------+
| tu    | CREATE TABLE "tu" (
  "s1" varchar(10) CHARACTER SET utf8 DEFAULT NULL
) ENGINE=Falcon DEFAULT CHARSET=latin1 |
+-------+---------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> delete from tu where char_length(s1)>1;
Query OK, 2586624 rows affected (9 hours 3 min 47.18 sec)

[23 Apr 2007 13:17] MySQL Verification Team

Thank you for the bug report.

[18 Sep 2007 20:06] Hakan Küçükyılmaz

Fixed with latest Falcon. Delete works under a minute now.

Best regards,

Hakan

[13 Nov 2007 8:22] MC Brown

A note has been added to the 6.0.3 changelog: 

Deleting a large number of records could sometimes take a significant amount of time.