Large database size & upgrade problem

[emir.yanliz]

hi
i have problem during upgrade
my database size is too large ( 1 G)
Run the database update process stops and i cant go to next step

Sorry for poor English
plz help me

[.m.]

you can try upgrading in your computer by using a local server (eg. xampp / wampp)

install a local server in your computer (I prefer using XAMPP)
put your forum offline. take back of the database & MyBB forum files.
make a copy of your MyBB forum in your computer by using database backup & files.
ensure that everything is working normal.

take a note of active plugins. disable plugins.
overwrite MyBB forum files with new version files and run upgrade script.

after successful upgrade transfer the files & database to your MyBB web server

upgrading guidance => http://docs.mybb.com/1.8/install/upgrade/