Who came across or can anyone have free access to a suitable csv upload for importing a catalog under Bitrix?

Question

1C-Bitrix

It is required to write an import for a catalog with goods and trade offers. Mostly text simple properties. You need a very high speed to update 20,000 products in one step on the crown on the server in 20 minutes. I tried importing bitrix csv from the box. Only works for 5,000 items ok, but trade offers don't work. Re-overwritten. Has anyone had experience in writing such imports and maybe there are some developments or wishes, tips on how to write efficiently. The site is already in production. I don't want to overwrite the base by accident.
I want to write 3 imports to create/update products, trade offers, product prices. And so that it could be hung on crowns, well, visitors could come in. Now with standard import it works according to a similar logic.
PS Huge request - do not insult Bitrix and do not offer your favorite freemvorki, but if you have your own ideas and approximate sequence in writing the script.

Answer 1

When I start writing imports, I usually try not to think about how to quickly update more products, but about how not to update more products.
The first and easiest optimization is to add one more thing to the product properties - HASH and write md5 there from the serialized array with which you want to update the product. Further, at the next update, before Update, you will calculate this Hash from the serialized array with which you want to update the product, and update the product only if it does not match the saved hash and write this new hash.
Such a scheme is very convenient if the source is not able to return only changed products or the product consists of several IB elements (Product + Trade Offer + Properties Element). In addition, remember that the price is also stored by a separate entity and you can do the same trick for it. Calculating md5 directly is much faster than making a record.
Also, make sure that your custom import has nothing but an update entry inside the loop. And then you had to see everything.
In general, writing 1000 products per minute into the database, without pictures, is complete nonsense. Any performance should suffice, unless of course it turns out that you do not have 100 TP for each product.
And yes - make sure that both the goods and the TP and all the IBs in which you write during import store properties in separate tables, and not in a common one.