          if index_name[0] == "_":
              index_name = index_name[1:]
          # If it's STILL too long, just hash it down
          if len(index_name) > self.connection.features.max_index_name_length:
              index_name = hashlib.md5(index_name).hexdigest()[:self.connection.features.max_index_name_length]
          # It can't start with a number on Oracle, so prepend D if we need to
          if index_name[0].isdigit():
              index_name = "D%s" % index_name[:-1]
          return index_name
  
 
</s> remove     models = [Author, AuthorWithM2M, Book, BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename, UniqueTest]
 </s> add     models = [
        Author, AuthorWithM2M, Book, BookWithLongName, BookWithSlug,
        BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename, UniqueTest,
    ] </s> remove from .models import Author, AuthorWithM2M, Book, BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename, UniqueTest
 </s> add from .models import (Author, AuthorWithM2M, Book, BookWithLongName,
    BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename,
    UniqueTest)
            index_name = hashlib.md5(force_bytes(index_name)).hexdigest()[:self.connection.features.max_index_name_length]
          if index_name[0] == "_":
              index_name = index_name[1:]
          # If it's STILL too long, just hash it down
          if len(index_name) > self.connection.features.max_index_name_length:
            index_name = hashlib.md5(force_bytes(index_name)).hexdigest()[:self.connection.features.max_index_name_length]
          # It can't start with a number on Oracle, so prepend D if we need to
          if index_name[0].isdigit():
              index_name = "D%s" % index_name[:-1]
          return index_name
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #21497 -- Forced conversion to bytes for very long index names 
django/db/backends/schema.py