Bug #11878 MySQL crashes when selecting information_schema
Submitted: 12 Jul 2005 8:27 Modified: 15 Sep 2005 14:07
Reporter: Chagh Email Updates:
Status: Can't repeat Impact on me:
None 
Category:MySQL Server Severity:S2 (Serious)
Version:5.0.7 OS:Windows (windows xp)
Assigned to: CPU Architecture:Any

[12 Jul 2005 8:27] Chagh
Description:
I use MySQL 5.0.7 on windows xp.When using information_schema and selecting from these tables i lost my connection to server(it crashed):
tables, views, columns and any thing about my DBs(instead of procs)

after a while trying to connect again with the same process it succeeded! and i could get information from information_schema tables without MySQL crash.
this is my error file when i saw it:

050706 15:03:18 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
050706 15:03:18 InnoDB: Starting log scan based on checkpoint at
InnoDB: log sequence number 0 2241193.
InnoDB: Doing recovery: scanned up to log sequence number 0 2241193
InnoDB: Last MySQL binlog file position 0 0, file name 
050706 15:03:18 InnoDB: Started; log sequence number 0 2241193
050706 15:03:18 [Note] C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections.
Version: '5.0.7-beta-nt' socket: '' port: 3306 Official MySQL 
binary
 

Chagh

How to repeat:
use information_schema and select from these tables:
tables, views, columns.
[12 Jul 2005 9:11] Aleksey Kishkin
tested on win xp sp2 and didn't get any error. If you have any ideas how to reproduce it, pls let us know and reopen this bug report

mysql> use information_schema
Database changed
mysql> select count(*) from tables;
+----------+
| count(*) |
+----------+
|       32 |
+----------+
1 row in set (0.03 sec)
[12 Jul 2005 13:00] Chagh
thank you
it doesn't occur always, it occurs sometimes and i do not know what does it depend on.
i used this select statement:
select * from tables;

and MySQL crshed.

Chagh
[12 Jul 2005 13:14] MySQL Verification Team
Could you please show for us your my.ini file ?
[13 Jul 2005 5:02] Chagh
this is my.ini file :

# MySQL Server Instance Configuration File
# ----------------------------------------------------------------------
# Generated by the MySQL Server Instance Configuration Wizard
#
#
# Installation Instructions
# ----------------------------------------------------------------------
#
# On Linux you can copy this file to /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options
# (@localstatedir@ for this installation) or to
# ~/.my.cnf to set user-specific options.
#
# On Windows you should keep this file in the installation directory 
# of your server (e.g. C:\Program Files\MySQL\MySQL Server 4.1). To
# make sure the server reads the config file use the startup option 
# "--defaults-file". 
#
# To run run the server from the command line, execute this in a 
# command line shell, e.g.
# mysqld --defaults-file="C:\Program Files\MySQL\MySQL Server 4.1\my.ini"
#
# To install the server as a Windows service manually, execute this in a 
# command line shell, e.g.
# mysqld --install MySQL41 --defaults-file="C:\Program Files\MySQL\MySQL Server 4.1\my.ini"
#
# And then execute this in a command line shell to start the server, e.g.
# net start MySQL41
#
#
# Guildlines for editing this file
# ----------------------------------------------------------------------
#
# In this file, you can use all long options that the program supports.
# If you want to know the options a program supports, start the program
# with the "--help" option.
#
# More detailed information about the individual options can also be
# found in the manual.
#
#
# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
#
[client]

port=3306

default-character-set=utf8

# SERVER SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this 
# file.
#
[mysqld]

# The TCP/IP Port the MySQL Server will listen on
port=3306

#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL/MySQL Server 5.0/"

#Path to the database root
datadir="C:/Program Files/MySQL/MySQL Server 5.0/Data/"

# The default character set that will be used when a new schema or table is
# created and no character set is defined
default-character-set=utf8

# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB

# The maximum amount of concurrent sessions the MySQL server will
# allow. One of these connections will be reserved for a user with
# SUPER privileges to allow the administrator to login even if the
# connection limit has been reached.
max_connections=735

# Query cache is used to cache SELECT results and later return them
# without actual executing the same query once again. Having the query
# cache enabled may result in significant speed improvements, if your
# have a lot of identical queries and rarely changing tables. See the
# "Qcache_lowmem_prunes" status variable to check if the current value
# is high enough for your load.
# Note: In case your tables change very often or if your queries are
# textually different every time, the query cache may result in a
# slowdown instead of a performance improvement.
query_cache_size=19M

# The number of open tables for all threads. Increasing this value
# increases the number of file descriptors that mysqld requires.
# Therefore you have to make sure to set the amount of open files
# allowed to at least 4096 in the variable "open-files-limit" in
# section [mysqld_safe]
table_cache=1500

# Maximum size for internal (in-memory) temporary tables. If a table
# grows larger than this value, it is automatically converted to disk
# based table This limitation is for a single table. There can be many
# of them.
tmp_table_size=16M

# How many threads we should keep in a cache for reuse. When a client
# disconnects, the client's threads are put in the cache if there aren't
# more than thread_cache_size threads from before.  This greatly reduces
# the amount of thread creations needed if you have a lot of new
# connections. (Normally this doesn't give a notable performance
# improvement if you have a good thread implementation.)
thread_cache_size=36

#*** MyISAM Specific options

# The maximum size of the temporary file MySQL is allowed to use while
# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
# If the file-size would be bigger than this, the index will be created
# through the key cache (which is slower).
myisam_max_sort_file_size=100G

# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method.  This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_max_extra_sort_file_size=100G

# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method.  This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_sort_buffer_size=8M

# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
# Do not set it larger than 30% of your available memory, as some memory
# is also required by the OS to cache rows. Even if you're not using
# MyISAM tables, you should still set it to 8-64M as it will also be
# used for internal temporary disk tables.
key_buffer_size=8M

# Size of the buffer used for doing full table scans of MyISAM tables.
# Allocated per thread, if a full scan is needed.
read_buffer_size=64K
read_rnd_buffer_size=256K

# This buffer is allocated when MySQL needs to rebuild the index in
# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
# into an empty table. It is allocated per thread so be careful with
# large settings.
sort_buffer_size=208K

#*** INNODB Specific options ***

# Use this option if you have a MySQL server with InnoDB support enabled
# but you do not plan to use it. This will save memory and disk space
# and speed up some things.
#skip-innodb

# Additional memory pool that is used by InnoDB to store metadata
# information.  If InnoDB requires more memory for this purpose it will
# start to allocate it from the OS.  As this is fast enough on most
# recent operating systems, you normally do not need to change this
# value. SHOW INNODB STATUS will display the current amount used.
innodb_additional_mem_pool_size=2M

# If set to 1, InnoDB will flush (fsync) the transaction logs to the
# disk at each commit, which offers full ACID behavior. If you are
# willing to compromise this safety, and you are running small
# transactions, you may set this to 0 or 2 to reduce disk I/O to the
# logs. Value 0 means that the log is only written to the log file and
# the log file flushed to disk approximately once per second. Value 2
# means the log is written to the log file at each commit, but the log
# file is only flushed to disk approximately once per second.
innodb_flush_log_at_trx_commit=1

# The size of the buffer InnoDB uses for buffering log data. As soon as
# it is full, InnoDB will have to flush it to disk. As it is flushed
# once per second anyway, it does not make sense to have it very large
# (even with long transactions).
innodb_log_buffer_size=1M

# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
# row data. The bigger you set this the less disk I/O is needed to
# access data in tables. On a dedicated database server you may set this
# parameter up to 80% of the machine physical memory size. Do not set it
# too large, though, because competition of the physical memory may
# cause paging in the operating system.  Note that on 32bit systems you
# might be limited to 2-3.5G of user level memory per process, so do not
# set it too high.
innodb_buffer_pool_size=97M

# Size of each log file in a log group. You should set the combined size
# of log files to about 25%-100% of your buffer pool size to avoid
# unneeded buffer pool flush activity on log file overwrite. However,
# note that a larger logfile size will increase the time needed for the
# recovery process.
innodb_log_file_size=20M

# Number of threads allowed inside the InnoDB kernel. The optimal value
# depends highly on the application, hardware as well as the OS
# scheduler properties. A too high value may lead to thread thrashing.
innodb_thread_concurrency=8
[13 Jul 2005 17:56] Jorge del Conde
I was unable to reproduce this crash using 5.0.7 under WInXP/sp2

mysql> SELECT COUNT(*)
    -> FROM INFORMATION_SCHEMA.COLUMNS A
    -> WHERE NOT EXISTS (SELECT * FROM
    -> INFORMATION_SCHEMA.TABLES B WHERE
    -> A.TABLE_SCHEMA = B.TABLE_SCHEMA AND
    -> A.TABLE_NAME = B.TABLE_NAME);
+----------+
| COUNT(*) |
+----------+
|        0 |
+----------+
1 row in set (3.56 sec)
[2 Aug 2005 14:49] Carsten Segieth
I could not reproduce the problem using the newest available Win* binaries. Also the test suite mentioned above now finishes as supposed.

mysql> SELECT VERSION();
+-----------------+
| VERSION()       |
+-----------------+
| 5.0.10a-beta-nt |
+-----------------+
1 row in set (0.00 sec)

mysql> SELECT COUNT(*)
    -> FROM INFORMATION_SCHEMA.COLUMNS A
    -> WHERE NOT EXISTS (SELECT * FROM
    -> INFORMATION_SCHEMA.TABLES B WHERE
    -> A.TABLE_SCHEMA = B.TABLE_SCHEMA AND
    -> A.TABLE_NAME = B.TABLE_NAME) ;
+----------+
| COUNT(*) |
+----------+
|        0 |
+----------+
1 row in set (9.83 sec)
[5 Aug 2005 6:20] Georg Richter
Do you use data files from an older version (< 5.0.7) ?
If yes, does this problem still occur if you create a new mysql data directory?
[11 Aug 2005 8:09] Kent TKC
Managed to reproduce this error
Running Windows XP Profesional SP2
---------------------------------------------------------------------------------------
mysql> select count(*)
    -> from information_schema.columns a
    -> where not exists (select * from
    -> information_schema.tables b where
    -> a.table_schema = b.table_schema and
    -> a.table_name = b.table_name);
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> select count(*)
    -> ;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
ERROR 2003 (HY000): Can't connect to MySQL server on 'localhost' (10061)
ERROR:
Can't connect to the server

mysql> quit
Bye

E:\Program Files\MySQL\MySQL Server 5.0\bin>net start mysql

The MySQL service was started successfully.

E:\Program Files\MySQL\MySQL Server 5.0\bin>mysql -u root -p
Enter password: ****
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 5.0.10a-beta-nt

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> select version();
+-----------------+
| version()       |
+-----------------+
| 5.0.10a-beta-nt |
+-----------------+
1 row in set (0.02 sec)
---------------------------------------------------------------------------------------

however on second attempt, it din produce any errors
---------------------------------------------------------------------------------------
mysql> select count(*)
    -> from information_schema.columns a
    -> where not exists (select * from
    -> information_schema.tables b where
    -> a.table_schema = b.table_schema and
    -> a.table_name = b.table_name);
+----------+
| count(*) |
+----------+
|        0 |
+----------+
1 row in set (4.61 sec)
---------------------------------------------------------------------------------------

having this problem too when browsing using Mysql Query Browse 1.1.6
Sometimes Mysql Service just got disconnected.
I looked into the Event Viewer

EventID : 7034

The MySQL service terminated unexpectedly.  It has done this 3 time(s).
[5 Sep 2005 23:00] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[10 Sep 2005 13:20] Chagh
hi,
I tried it with version 5.0.12 also. It is different this time. I had some SPs from my older data. they remained when i upgraded my server. some of these SPs had "prepare statemnt" in them. I could not see them in MySQL QueryBrowser('cause of MySQL version Query Browser doesn't show SPs). so i used navicat. by navicat i tried to drop these SPs but i couldn't (it gave me the error: prepare is not allowed in SPs). then i tried to drop these SPs from MySQL Client but i got the same error.
after that any time i tried to use tables of information_schema, procs tale of mysql database and ... the server crashed and i restarted it manually.
the error i get after crashing is:"mysqld_nt.exe - Application error: The instruction at ''0x004e7866" referenced memory at ''0x00000000''. The memory could not be "Read"."
Please tell me in detail what feedback should i give.
Thanks
Chagh
[15 Sep 2005 14:07] Valeriy Kravchuk
The original select works on 5.0.12-beta-nt:

mysql> select version();
+----------------+
| version()      |
+----------------+
| 5.0.12-beta-nt |
+----------------+
1 row in set (0.00 sec)

mysql> SELECT COUNT(*)
    -> FROM INFORMATION_SCHEMA.COLUMNS A
    -> WHERE NOT EXISTS (SELECT * FROM
    -> INFORMATION_SCHEMA.TABLES B WHERE
    -> A.TABLE_SCHEMA = B.TABLE_SCHEMA AND
    -> A.TABLE_NAME = B.TABLE_NAME);
+----------+
| COUNT(*) |
+----------+
|        0 |
+----------+
1 row in set (38.86 sec)

As for procedures from the previous versions with the prepared statements in
them... There are several bug reports already about upgrading of pre-5.0.10 databases with SPs to 5.0.x, where x >= 10. The real workaround is to dump, install fresh version, and restore all you databases, if they include stored procedures.

As for prepared statements, they are simply not supported in SPs in 5.0.12; see the manual (http://dev.mysql.com/doc/mysql/en/routine-restrictions.html):

"Stored routines cannot contain arbitrary SQL statements. The following statements are disallowed within stored routines:

-  CHECK TABLES
-  LOCK TABLES, UNLOCK TABLES
-  LOAD DATA, LOAD TABLE

SQL prepared statements (PREPARE, EXECUTE, DEALLOCATE PREPARE). 

Implication: You cannot use dynamic SQL within stored routines (where you construct dynamically statements as strings and then execute them). This restriction is lifted as of MySQL 5.0.13 for stored procedures; it still applies to stored functions and triggers."

So, wait until 5.0.13 released, make a dump, then a fresh install, restore your procedures, reread the documentation and then open a new bug report, in case of any undocumented behaviour of your stored procedures.