Hi Damir,
Check your "IBM Informix Guide to SQL Syntax" documentation Volume 1 if you have it handy.
in dbaccess
RENAME DATABASE dog_db TO cat_db
note: the dog_db database must not be opened or in-use when it is being renamed so you can do this:
in dbaccess, select any database other than the dog_db database; I'll call it mouse_db. You don't want to change mouse_db but you're using it as a means to RENAME dog_db to cat_db.
While in mouse_db, issue the RENAME command.
results:
mouse_db remains unchanged
dog_db is now cat_db
Good luck,
Mike