Details
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Type:
Bug
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Status: Closed
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Priority:
Major
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Resolution: Cannot Reproduce
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Affects Version/s: 5.5.33
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Fix Version/s: None
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Component/s: None
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Labels:None
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Environment:VMware Workstation, Fedora Core 19 vanilla install
mysql Ver 15.1 Distrib 5.5.32-MariaDB, for Linux (x86_64) using readline 5.1
Description
SELECT SLEEP(4), ID FROM Region;
The above statement hangs indefinitely instead of 4 seconds like intended.
EXPLAIN also doesn't show too much information.
EXPLAIN SELECT SLEEP(4), ID FROM Region; +------+-------------+--------+-------+---------------+---------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+--------+-------+---------------+---------+---------+------+------+-------------+ | 1 | SIMPLE | Region | index | NULL | PRIMARY | 4 | NULL | 1 | Using index | +------+-------------+--------+-------+---------------+---------+---------+------+------+-------------+ SHOW CREATE TABLE Region output: CREATE TABLE `Region` ( `ID` int(11) NOT NULL AUTO_INCREMENT, `Name` varchar(45) COLLATE utf8_unicode_ci NOT NULL, PRIMARY KEY (`ID`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
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Hi,
I tried both empty and non-empty tables and views. They all hang.
I'll run that later tonight, but I'm sure you can also reproduce it.
-Dorian
Sent from my iPhone
Actually I can't, that's why I'm asking. It looks pretty consistent to me, SELECT on an empty table returns immediately, on a 1-row table it takes 4 sec, on 2-row table it takes 8 sec, etc.
MariaDB [test]> select count
from Region;
----------
| count |
----------
| 0 |
----------
1 row in set (0.00 sec)
MariaDB [test]> SELECT SLEEP(4), ID FROM Region;
Empty set (0.01 sec)
MariaDB [test]> insert into Region (Name) Values ('Region1');
Query OK, 1 row affected (0.03 sec)
MariaDB [test]> SELECT SLEEP(4), ID FROM Region;
------------+
| SLEEP(4) | ID |
------------+
| 0 | 3 |
------------+
1 row in set (4.01 sec)
MariaDB [test]> insert into Region (Name) Values ('Region2');
Query OK, 1 row affected (0.04 sec)
MariaDB [test]> SELECT SLEEP(4), ID FROM Region;
------------+
| SLEEP(4) | ID |
------------+
| 0 | 3 |
| 0 | 4 |
------------+
2 rows in set (8.00 sec)
MariaDB [test]> show create table Region;
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Region | CREATE TABLE `Region` ( `ID` int(11) NOT NULL AUTO_INCREMENT, `Name` varchar(45) COLLATE utf8_unicode_ci NOT NULL, PRIMARY KEY (`ID`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)
Closing for now according to the previous comment. If you have more information, please comment to re-open the bug.
Hi,
Do you mean that it hangs on an empty table?
Could you please run SHOW FULL PROCESSLIST from a different connection while the query hangs?
Thanks.