Index the document checksum field for faster searches by checksum.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

docs/releases/2.5.rst

@@ -53,6 +53,7 @@ Other Changes
   document types from either the metadata type list or document type list.
   GitLab issue #373.
 - Add support to search documents by their checksums.
+- The document checksum field is now indexed for faster searches by checksum.
 
 Removals
 --------

mayan/apps/documents/migrations/0038_auto_20170705_1942.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.7 on 2017-07-05 19:42
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '0037_auto_20161231_0617'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='documentversion',
+            name='checksum',
+            field=models.TextField(
+                blank=True, db_index=True, editable=False, null=True,
+                verbose_name='Checksum'
+            ),
+        ),
+    ]

mayan/apps/documents/models.py

@@ -383,7 +383,8 @@ class DocumentVersion(models.Model):
         blank=True, editable=False, max_length=64, null=True
     )
     checksum = models.TextField(
-        blank=True, editable=False, null=True, verbose_name=_('Checksum')
+        blank=True, db_index=True, editable=False, null=True,
+        verbose_name=_('Checksum')
     )
 
     def __str__(self):