text: from django.db import models
  
  
  class Book(models.Model):
      title = models.CharField(max_length=50)
      author = models.CharField(max_length=50)
      pages = models.IntegerField(db_column="page_count")
      shortcut = models.CharField(max_length=50, db_tablespace="idx_tbls")
      isbn = models.CharField(max_length=50, db_tablespace="idx_tbls")
      barcode = models.CharField(max_length=31)
  
      class Meta:
          indexes = [
              models.Index(fields=["title"]),
              models.Index(fields=["isbn", "id"]),
              models.Index(
                  fields=["barcode"], name="%(app_label)s_%(class)s_barcode_idx"
              ),
          ]
  
  
  class AbstractModel(models.Model):
      name = models.CharField(max_length=50)
      shortcut = models.CharField(max_length=3)
  
      class Meta:
          abstract = True
          indexes = [
              models.Index(fields=["name"]),
              models.Index(fields=["shortcut"], name="%(app_label)s_%(class)s_idx"),
          ]
  
  
  class ChildModel1(AbstractModel):
      pass
  
  
  class ChildModel2(AbstractModel):
      pass
  