Hello everyone, I hope you're all doing well.

I have an interesting requirement to discuss. I'm trying to migrate data from V15 to V18. The main problem is that the company that sold us V15 no longer exists, so I don't have the updated code for V18, which prevents me from using the Odoo.sh update process.

With this in mind, I only have the following options left: 

1. Pay for a perpetual V15 subscription for local or web use, maintaining data persistence.

2. Perform a schema-to-schema mapping to migrate all the information.

3. Manually upload all the data to the system using CSV and UI, setting computed data as editable to facilitate the loading of auto-generated data (sequences, amounts, etc.).

Each option has its advantages and disadvantages, both objectively and subjectively. 

1. Subscription Payment.

The company doesn't want to pay an extra membership fee just to maintain persistence. I tried a local installation, but the community version is obviously not compatible with our enterprise version, and this version requires a license. 

2. Schema-to-Schema Mapping.

This is a considerably lengthy and extremely methodical task, especially if data integrity is to be maintained. For our database, this would involve validating a total of 200 tables for mapping, with any number of columns. After this, migration scripts would need to be created for each model, although this is easier with AI. 

3. Manual Loading.

This, like the previous option, is considerably lengthy, but more mechanical than methodical. It would involve a total of two years' worth of data, and would only require manually setting up financial and inventory transaction data, since data such as customers, products, opportunities, quotes, and tickets can be easily handled via a script. In total, this would involve approximately 3,000 accounting entries. The good thing is that we could use an RPA to handle the setup record by record. The complexity lies in the computerized data; doing things manually could cause problems if the procedure isn't followed in the order it was executed. A practical example of this would be inventory operations, where the receipt date field is automatically assigned the current date. 

I've been thinking a lot about which of the last two options would be the most practical for a migration with a 3- to 4-month timeframe, and I'd love to have more perspectives to determine an option, or a new alternative.

Thank you in advance. Have a great weekend.