Creating a new Bitrix site based on the old one?

Question

1C-Bitrix

There is a corporate website along with an Internet store, quite large, on Bitrix. They did it for quite some time. Now the question is to redo it completely from scratch + add new functionality, also to Bitrix. But to fasten to it an old DB. How to do it right? And is it possible? As I understand it, the usual transfer of a dump, as when migrating to another hosting, will not work here?

Answer 1

You can create a separate site within the framework of multisite.
And connect the old infoblock to it.
Or transfer the data to a new infoblock, taking into account the new architecture.
It is worth paying attention to the handlers in init.php

Answer 2

So from scratch or to fasten the old database to it?
And what do you even call a DB?
In fact, there are two ways:
1 Take the old site and rewrite the components and their templates. Thus, you change, relatively speaking, only controllers and viewers. The database remains completely the same, along with the base of goods.
2 Make a completely new site from scratch, and transfer the goods to it using import / export procedures, but most likely not standard ones (since in their cases the database structure will most likely be similar to the original one, and in this case, why not use option 1 ), but self-written ones. This is where you change everything.
Which option to use depends on how the database structure matches your ideas about what the site architecture should be.
If the current architecture is good, use approach 1. If not, choose approach 2. Any
other options? Yes.
Hybrid approach - you take the current site and create a new one based on it and the database, using new IBs and entities for the new site. You save the old IB and entities on the site, and transfer the given one to the new ones using migration scripts.
I love this hybrid option - old data can be left on the site for as long as you like and you can always refer to it. Scripts for transferring data from one IB to another are usually much simpler than import / export scripts.
The only negative is a small mess in the admin panel, but upon completion of the work, you can demolish the old information security in battle and put things in order.