Database scaling & optimization
Indexing, connection pooling, read replicas, query tuning, and throughput-aware SQL.
How to Eager Load with JOIN to Reduce N+1 Queries in Python
Demonstrates eager loading with a SQL JOIN to reduce N+1 query patterns down to a single database call when fetching related data.
import sqlite3
def eager_load_join_reduce(mock_db_path=":memory:"):
"""Demonstrate eager loading where joins reduce query count from N+1 to 1."""
conn = sqlite3.connect(mock_db_path)
cursor = conn.cursor()
cursor.executescript(
"""
CREATE TABLE authors (id INTEGER PRIMARY KEY, name TE…How to Implement Read-After-Write Consistency Mock in Python
Simulate strong versus eventual read-after-write consistency with a primary and replica store, demonstrating the difference in data visibility over time.
import time
class MockStorage:
def __init__(self, write_delay=0.1):
self.store = {}
self.replica = {}
self.write_delay = write_delay
def write(self, key, value):
# Write to primary storage immediately
self.store[key] = value
# Simulate async replication delay
…Offset vs Keyset Pagination in Python
Demonstrate offset-based pagination and keyset (cursor) pagination with a simple in-memory dataset, showing how each returns pages of records.
"""Demonstrate pagination using offset vs keyset (cursor) approach."""
ITEMS = [
{"id": 1, "name": "Alice"},
{"id": 2, "name": "Bob"},
{"id": 3, "name": "Carol"},
{"id": 4, "name": "David"},
{"id": 5, "name": "Eve"},
]
def offset_paginate(items, page, page_size):
"""Return a page using offset…Two Phase Commit Cross Shard Mock in Python
Simulates a two-phase commit across shards with failure handling to demonstrate distributed transaction coordination in Python.
"""Mock cross-shard two-phase commit with caution handling."""
class Shard:
def __init__(self, name):
self.name = name
self.prepared = False
self.committed = False
self.aborted = False
def prepare(self):
# Simulate potential failure (1 in 3 chance on third shard)
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Database scaling & optimization — Python code examples
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