jasonwalkeryung

"""
Unit test fixture for testing with read replicas as described in:
https://gist.github.com/jasonwalkeryung/5133383d66782461cdc3b4607ae35d98
"""
import pytest
from sqlalchemy_replica import db


@pytest.fixture
def rollback():

jasonwalkeryung

"""This is not the full code. We do a lot of stuff to clean up connections, particularly for unit testing."""
import sqlalchemy
from sqlalchemy.orm import Query, Session, scoped_session, sessionmaker

CONFIG_KEY_SQLALCHEMY_BINDS = 'SQLALCHEMY_BINDS'
CONFIG_KEY_SQLALCHEMY_RO_BINDS = 'SQLALCHEMY_READ_ONLY_BINDS'

class Config:
    # These default values are for testing. In a deployed environment, they would be three separate instances.
    SQLALCHEMY_DATABASE_URI = 'postgresql://localhost/branded_dev'

jasonwalkeryung

psql=> explain analyze select distinct users.id, users.name, users.email from users where reverse(users.email) like reverse('%example.com');
                                                                 QUERY PLAN                                                                  
---------------------------------------------------------------------------------------------------------------------------------------------
 HashAggregate  (cost=54001.19..54170.10 rows=16891 width=71) (actual time=0.114..0.154 rows=25 loops=1)
   Group Key: id, name, email
   ->  Bitmap Heap Scan on users  (cost=845.69..53874.51 rows=16891 width=71) (actual time=0.036..0.092 rows=25 loops=1)
         Filter: (reverse((email)::text) ~~ 'moc.elpmaxe%'::text)
         Heap Blocks: exact=25
         ->  Bitmap Index Scan on idx_users_email_reverse  (cost=0.00..841.46 rows=16891 width=0) (actual time=0.023..0.023 rows=25 loops=1)
               Index Cond: ((reverse((email)::text) ~>=~ 'moc.elpmaxe'::text) AND (reverse((email)::text)

jasonwalkeryung

psql=> explain analyze select distinct users.id, users.name, users.email from users where users.email ilike '%example%';
                                                       QUERY PLAN                                                       
------------------------------------------------------------------------------------------------------------------------
 Unique  (cost=290618.12..290621.50 rows=338 width=71) (actual time=5458.523..5458.560 rows=41 loops=1)
   ->  Sort  (cost=290618.12..290618.97 rows=338 width=71) (actual time=5458.521..5458.539 rows=41 loops=1)
         Sort Key: id, name, email
         Sort Method: quicksort  Memory: 28kB
         ->  Seq Scan on users  (cost=0.00..290603.92 rows=338 width=71) (actual time=97.851..5458.380 rows=41 loops=1)
               Filter: ((email)::text ~~* '%example%'::text)
               Rows Removed by Filter: 3378716

jasonwalkeryung

class Product(ExampleModel):
    name = Column(String, nullable=False)
    description = Column(Text)
    list_price = Column(Numeric)
    sell_price = Column(Numeric)
    variants = relationship('Variant', backref="product")


class Variant(ExampleModel):
    product_id = Column(ForeignKey('products.id'))

jasonwalkeryung

Keybase proof

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• I am jasonwalkeryung on github.
• I am jasonwalkeryung (https://keybase.io/jasonwalkeryung) on keybase.
• I have a public key ASBV0DZBlZ-vte-AuUa7IUetss2SpYGUZJU8p6r8p9Im0go

To claim this, I am signing this object: