For Auto increment field, Link field is created as varchar so when joining the table query is running slow due to data type missmatch.

[amrishshah]

I purpose following changes in the file apps/frappe/frappe/database/schema.py

In Class DbColumn

Pass variable to get_definition as shown below

Pass variable in build_for_alter_table as shown below

Make changes in the get_definition function

Actual is_link_doctype_autoincrement function

Complete File
schema.txt

[amrishshah]

Also casting need to be done for second part as mentioned in #24454

[ankush]

related: #25310