[Feature Request][Spark] Allow schema evolution from numerics to string

[antonio-yuen-zocdoc]

Feature request

Which Delta project/connector is this regarding?

• [x] Spark
• [ ] Standalone
• [ ] Flink
• [ ] Kernel
• [ ] Other (fill in here)

Overview

I have an interesting problem with how my company evolves their data naturally within our own ecosystem. We have a bunch of ids that starts off as longs but eventually evolves into strings. This causes delta to oftentimes break and require manual intervention for schema evolutions.

Ideally we can add functionality that allows for automatic schema evolution from numerics into strings.

Willingness to contribute

The Delta Lake Community encourages new feature contributions. Would you or another member of your organization be willing to contribute an implementation of this feature?

• [ ] Yes. I can contribute this feature independently.
• [x] Yes. I would be willing to contribute this feature with guidance from the Delta Lake community.
• [ ] No. I cannot contribute this feature at this time.