I have a self.env['my.model'].search([]) in a function called by a field default. This field is in a model that inherits from res.partner. It works well if the module is installed. But fails when I install the module in a new database. The errors is that it can't find the relation my_model in the database.

I supose that during installation, the new my_model model exists only for odoo, but is not accessible in the postgresql database. The search function calls a SQL query and it fails. Res.partner exists already, and it try to compute all the default fields and calls the SQL query before it finish the installation. 

There is a way to ask odoo if the model exists before doing a search([])?

Thanks in advance.