Lost left/right cursor keys in VIM insert mode?

When I edit .sql file in VIM, I can't use left/right cursor keys while in insert mode. In normal mode they work just fine. In another file types - they work fine as well. in ~/.vim/ftplugin/sql.vim there is bunch of "iab"s, but not much more.

I found out that when running vim with standard vimrc, not-customized, the problem is not existing.

What could be wrong? Is there any option that could have been set, that disables some (up and down work) cursor keys in insert mode ?!

It may be that somehow the keys have become mapped to a command. Type :mapCtrlV→ to see if the right arrow has been mapped, and the same for left arrow after.

Add the following to your ~/.vimrc or ~/.vim/ftplugin/sql.vim file:

let g:omni_sql_no_default_maps = 1