Add some indexes.

accountant/api/models/operations.py

@@ -25,26 +25,33 @@ from accountant import db
 class Operation(db.Model):
     id = db.Column(db.Integer, primary_key=True)
 
-    operation_date = db.Column(db.Date, nullable=False)
+    operation_date = db.Column(
+        db.Date,
+        nullable=False,
+        default=arrow.now().date(),
+        server_default=func.current_date(),
+        index=True
+    )
     label = db.Column(db.String(500), nullable=False)
     value = db.Column(db.Numeric(15, 2), nullable=False)
 
     scheduled_operation_id = db.Column(
         db.Integer,
-        db.ForeignKey('scheduled_operation.id')
+        db.ForeignKey('scheduled_operation.id'),
+        index=True
     )
 
     scheduled_operation = db.relationship(
         "ScheduledOperation", backref=db.backref('entry', lazy="dynamic")
     )
 
-    account_id = db.Column(db.Integer, db.ForeignKey('account.id'))
+    account_id = db.Column(db.Integer, db.ForeignKey('account.id'), index=True)
 
     account = db.relationship(
         'Account', backref=db.backref('operation', lazy="dynamic")
     )
 
-    category = db.Column(db.String(100), nullable=True)
+    category = db.Column(db.String(100), nullable=True, index=True)
 
     pointed = db.Column(
         db.Boolean,