How to enable inno-db support on MySql 5 installed above MySql 4?

Question

How to enable inno-db support on installed instance of MySql?

I have installed mysql-5.0.67-win32. 'InnoDB' is 'DISABLED' when executing 'show engines'. According to documentation MySql is compiled with support of inno-db (From doc: A value of DISABLED occurs either because the server was started with an option that disables the engine, or because not all options required to enable it were given.)

In my.ini I commented line with 'skip-innodb'. This didn't help. All other inno-db related variables remain unchanged.

I have performed some unusual action before I experienced described situation. I have mysql-4.0.17-win installed. I uninstall it and after this installed mysql-5.0.67-win32. In installation wizard I chose MyISAM support only (as far as I understand I disabled inno-db support in such way. When I tried to reinstall with support of inno-db I had problems of using my previous database 'mysql' with account information).

MySQL documentation says that I should use mysqldump to export data and after this to import exported data in process of upgrade. I tried to do so, but when importing data I obtained message about syntax error (I think that it is connected with some incompatibilities of 4-th and 5-th version of mysql)

Answer 1

Maybe you have inno-db disabled in the global configuration file. On Linux this would be something like /etc/mysql/my.cnf - maybe Windows has a similar global conf-file.

Answer 2

Should be enabled by default. There are some situations where wrong permissions on the MySQL lib folder cause InnoDB to bark. Check your MySQL error log for permission errors.

Answer 3

I do have the following innodb options in my.ini. It is a very minimal configuration, so dont' use this values if you would like mysql to have a good performance. Please restart mysql after a change of my.ini.

#*** INNODB Specific options ***
innodb_data_home_dir="C:/mysqldata/"
#skip-innodb
innodb_additional_mem_pool_size=120M
innodb_flush_log_at_trx_commit=1
innodb_log_buffer_size=16M
innodb_buffer_pool_size=10M
innodb_log_file_size=2M
innodb_thread_concurrency=8

Answer 4

Make sure you are changing the correct my.ini file. On Windows this is read from many locations. The order is:

1. WINDIR\my.ini, WINDIR\my.cnf
2. C:\my.ini, C:\my.cnf
3. INSTALLDIR\my.ini, INSTALLDIR\my.cnf
4. defaults-extra-file

Type mysql --help in the command prompt to see the actual order on your computer e.g.:

Default options are read from the following files in the given order: C:\my.ini C:\my.cnf C:\WINDOWS\my.ini C:\WINDOWS\my.cnf C:\Program Files\MySQL\M ySQL Server 5.0\my.ini C:\Program Files\MySQL\MySQL Server 5.0\my.cnf

Answer 5

have you checked the startup parameters? maybe the shell script or batch file that you use to start up the server disable the engine on the command line.. IIRC command line flags trumps the .ini settings.

Answer 6

I have resolved the problem.

In short: I was not able to dump databases on MySql4 and restore it on MySql5 due to some strange syntactic errors when importing data.

I tried after installation to override MySql5 databases with old ones, including database 'mysql'. It works ok but I was not able to enable inno-db support. (In such way I even was able to use function PASSWORD for old passwords (instead of OLD_PASSWORD))

Since database structure of 'mysql' is changed in 5 version I tried to install MySql5 again and copied my old databases except 'mysql' one. After this I updated 'mysql' database with corrected version of exported data from 'mysql'. In such a way I obtained mysql 5 working.

After all I also executed
mysqlcheck --all-databases --auto-repair
to upgrade my tables.

P.S. Thank to authors of all answers which hint me to the correct way of resolving problem.