Database scaling & optimization
Indexing, connection pooling, read replicas, query tuning, and throughput-aware SQL.
B-Tree Insert and In-Order Traversal in Python
Simulates a B-tree (order 2) with insert and split logic, then prints keys in sorted order via in-order traversal.
class BTreeNode:
def __init__(self, leaf=False):
self.leaf = leaf
self.keys = []
self.children = []
def is_full(self, t):
return len(self.keys) == 2 * t - 1
class BTree:
def __init__(self, t=2):
self.t = t
self.root = BTreeNode(leaf=True)
def insert(s…
How to Simulate Colocated Shard Joins in Python
Groups shards by their node and merges co-located shards into a single logical unit, checking capacity constraints.
import random
from collections import defaultdict
def simulate_colocated_shards_join(nodes: list[dict], shards: list[dict]) -> dict:
"""
Simulates the join of co-located shards (on the same node) into a single
logical shard. Returns the resulting node-to-shard mapping.
Each node: {'id': str, 'capaci…
How to mock batch commit of transactions in Python
Simulate a transaction batch writer with commit, rollback, and summary logic to test database write patterns without a real database.
import json
from datetime import datetime, timezone
class TransactionBatch:
def __init__(self):
self.pending = []
self.committed = []
self._log = []
def add(self, operation):
self.pending.append(operation)
def commit(self):
if not self.pending:
return …
How to mock directory-based sharding in Python
Simulates distributing files into logical shards using a deterministic hash of each filename, mocking how a database might shard rows across nodes.
import os
import hashlib
from collections import defaultdict
from pathlib import Path
def get_shard_for_key(key: str, num_shards: int) -> int:
"""Return a deterministic shard index (0..num_shards-1) for a key."""
digest = hashlib.md5(key.encode('utf-8')).hexdigest()
return int(digest, 16) % num_shards
…
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Database scaling & optimization — Python code examples
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