How to account sales of large volume. For instance, we are raising some thousand invoices per day. But we are entering the sales once in a week as lump sum. It will be impractical to enter every invoice. How in the distribution channels the sales were to be entered?

If you are creating a thousand invoices per day you should probably look into some software that will generate the invoice and post it to a journal. If you are not interested in that, post the sales lump sum sales by day not by week. This will give you a better measure of when you are selling your product. If you can post by hour, that would help also.