text: from django.db import models
  from postgres_copy import CopyManager
  
  
  class Dbsnp(models.Model):
      """Information of the DBSNP database."""
  
      #: Genome build
      release = models.CharField(max_length=32)
      #: Variant coordinates - chromosome
      chromosome = models.CharField(max_length=32)
      #: Variant coordinates - 1-based start position
      start = models.IntegerField()
      #: Variant coordinates - end position
      end = models.IntegerField()
      #: Variant coordinates - UCSC Bin
      bin = models.IntegerField()
      #: Variant coordinates - reference
      reference = models.CharField(max_length=512)
      #: Variant coordinates - alternative
      alternative = models.CharField(max_length=512)
      #: DbSNPs RsID
      rsid = models.CharField(max_length=16)
  
      #: Allow bulk import
      objects = CopyManager()
  
      class Meta:
          # The uniqueness constraint will automatically add an index, no need to create a second.
          unique_together = ("release", "chromosome", "start", "reference", "alternative")
  