title: DROP DATABASE crash mysql server
body: <p>I've a little problem when I want to DROP my database.</p>
  
  <p>When I execute :</p>
  
  <pre><code>DROP DATABASE `mydb`;
  </code></pre>
  
  <p>MySQL returns :</p>
  
  <pre><code>Error Code: 2013. Lost connection to MySQL server during query
  </code></pre>
  
  <p>(Executed from phpmyadmin, I'm disconnected and redirected to login/password)</p>
  
  <p>The problem can be a fantom table.</p>
  
  <p>If I execute :</p>
  
  <pre><code>CHECK TABLE `mydb`.`mytable`
  </code></pre>
  
  <p>I have :</p>
  
  <pre><code>Error Code: 1146. Table 'mydb.mytable' doesn't exist
  </code></pre>
  
  <p>But if I execute :</p>
  
  <pre><code>CREATE TABLE IF NOT EXISTS `mydb`.`mytable` ...
  </code></pre>
  
  <p>I have :</p>
  
  <pre><code>Error Code: 1050. Table '`mydb`.`mytable`' already exists
  </code></pre>
  
  <p>"SELECT *" says it doesn't exist to.</p>
  
  <p>I have tried innodb_force_recovery 6 when I execute the DROP DATABASE :</p>
  
  <pre><code>InnoDB: Load table 'mydb/mytable' failed, the table has missing foreign key indexes. Turn off 'foreign_key_checks' and try again.140417 11:09:55 InnoDB: Assertion failure in thread 2797190000 in file row0mysql.c line 3683
  InnoDB: Failing assertion: table
  InnoDB: We intentionally generate a memory trap.
  InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
  InnoDB: If you get repeated assertion failures or crashes, even
  InnoDB: immediately after the mysqld startup, there may be
  InnoDB: corruption in the InnoDB tablespace. Please refer to
  InnoDB: http://dev.mysql.com/doc/refman/5.5/...-recovery.html
  InnoDB: about forcing recovery.
  09:09:55 UTC - mysqld got signal 6 ;
  This could be because you hit a bug. It is also possible that this binary
  or one of the libraries it was linked against is corrupt, improperly built,
  or misconfigured. This error can also be caused by malfunctioning hardware.
  We will try our best to scrape up some info that will hopefully help
  diagnose the problem, but since we have already crashed, 
  something is definitely wrong and this may fail.
  
  key_buffer_size=16777216
  read_buffer_size=131072
  max_used_connections=1
  max_threads=151
  thread_count=1
  connection_count=1
  It is possible that mysqld could use up to 
  key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 346075 K bytes of memory
  Hope that's ok; if not, decrease some variables in the equation.
  
  Thread pointer: 0xffffffffb9523670
  Attempting backtrace. You can use the following information to find out
  where mysqld died. If you see no messages after this, something went
  terribly wrong...
  stack_bottom = ffffffffa6b9b32c thread_stack 0x30000
  /usr/sbin/mysqld(my_print_stacktrace+0x33)[0xb7329743]
  /usr/sbin/mysqld(handle_fatal_signal+0x4a4)[0xb71ca984]
  [0xb6e7f400]
  /lib/i386-linux-gnu/i686/cmov/libc.so.6(abort+0x182)[0xb6b8bd72]
  /usr/sbin/mysqld(+0x4e1e3b)[0xb737fe3b]
  /usr/sbin/mysqld(+0x4c8d6a)[0xb7366d6a]
  /usr/sbin/mysqld(+0x32ca05)[0xb71caa05]
  /usr/sbin/mysqld(_Z24plugin_foreach_with_maskP3THDPFcS0_P13st_plugin_intPvEijS3_+0x1d1)[0xb70ac121]
  /usr/sbin/mysqld(_Z16ha_drop_databasePc+0x3f)[0xb71cbb9f]
  /usr/sbin/mysqld(_Z11mysql_rm_dbP3THDPcbb+0xc13)[0xb707b073]
  /usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x4477)[0xb709fff7]
  /usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x254)[0xb70a2f54]
  /usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x2000)[0xb70a5910]
  /usr/sbin/mysqld(_Z10do_commandP3THD+0xce)[0xb70a63de]
  /usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x123)[0xb7155983]
  /usr/sbin/mysqld(handle_one_connection+0x50)[0xb7155ab0]
  /lib/i386-linux-gnu/i686/cmov/libpthread.so.0(+0x5c39)[0xb6e5dc39]
  /lib/i386-linux-gnu/i686/cmov/libc.so.6(clone+0x5e)[0xb6c34d4e]
  
  Trying to get some variables.
  Some pointers may be invalid and cause the dump to abort.
  Query (ffffffffb9599500): DROP DATABASE `mydb`
  Connection ID (thread ID): 2
  Status: NOT_KILLED
  
  The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
  information that should help you find out what is causing the crash.
  </code></pre>
  
  <p>Ideas ?</p>