Hello everyone, 

why this line is inside the loop?

https://github.com/odoo/odoo/blob/132c7e75e57321c77aac9250a2587c74c5da7857/addons/account/models/account_move.py#L1364

We were removing 100k~ account.move.line records for testing purposes. It took ages. So we do some little investigation and saw this, we took out from the loop the process duration became minutes from hours.

Regards from Projet
sign_partial_line = sign if partial_line.credit_move_id == line else (-1 * sign)
                amount += sign_partial_line * partial_line.amount
                
                if line.currency_id:
                    if partial_line.currency_id and partial_line.currency_id == line.currency_id:
                        amount_residual_currency += sign_partial_line * partial_line.amount_currency
                    else:
                        if line.balance and line.amount_currency:
                            rate = line.amount_currency / line.balance
                        else:
                            date = partial_line.credit_move_id.date if partial_line.debit_move_id == line else partial_line.debit_move_id.date
                            rate = line.currency_id.with_context(date=date).rate
                        amount_residual_currency += sign_partial_line * line.currency_id.round(partial_line.amount * rate)
            
            
            reconciled = False
            digits_rounding_precision = line.company_id.currency_id.rounding
            if float_is_zero(amount, precision_rounding=digits_rounding_precision):
                if line.currency_id and line.amount_currency:
                    if float_is_zero(amount_residual_currency, precision_rounding=line.currency_id.rounding):
                        reconciled = True
                else:
                    reconciled = True
            line.reconciled = reconciled
            line.amount_residual = line.company_id.currency_id.round(amount * sign)
            line.amount_residual_currency = line.currency_id and line.currency_id.round(amount_residual_currency * sign) or 0.0
    @api.depends('debit', 'credit')
    def _store_balance(self):