Migrate to postgres, add memcache and vastly improve available equipment instance query time from 1min 30 seconds to 12 seconds

equipment_tracker/transactions/migrations/0002_alter_transaction_transaction_status.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.0.1 on 2024-01-06 16:49
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('transactions', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='transaction',
+            name='transaction_status',
+            field=models.CharField(choices=[('Pending Approval', 'Pending Approval'), ('Approved', 'Approved'), ('Rejected', 'Rejected'), ('Cancelled', 'Cancelled'), ('Borrowed', 'Borrowed'), ('Returned: Pending Checking', 'Returned: Pending Checking'), ('With Breakages: Pending Resolution', 'With Breakages: Pending Resolution'), ('Finalized', 'Finalized')], db_index=True, default='Pending', max_length=40),
+        ),
+    ]

equipment_tracker/transactions/models.py

@@ -2,6 +2,7 @@ from django.db import models
 from accounts.models import CustomUser
 from equipments.models import EquipmentInstance
 from django.utils.timezone import now
+from django.core.cache import cache
 
 
 class Transaction(models.Model):
@@ -34,9 +35,13 @@ class Transaction(models.Model):
         CustomUser, on_delete=models.SET_NULL, null=True, related_name='teacher_transactions')
     equipments = models.ManyToManyField(EquipmentInstance)
     transaction_status = models.CharField(
-        max_length=40, choices=TRANSACTION_STATUS_CHOICES, default='Pending')
+        max_length=40, choices=TRANSACTION_STATUS_CHOICES, default='Pending', db_index=True)
     subject = models.TextField(max_length=128)
     timestamp = models.DateTimeField(default=now, editable=False)
 
     def __str__(self):
         return f"Transaction #{self.id} under {self.teacher} by {self.borrower}"
+
+    def save(self, *args, **kwargs):
+        cache.delete('non_finalized_transactions')
+        return super().save(*args, **kwargs)