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Database scaling & optimization

Indexing, connection pooling, read replicas, query tuning, and throughput-aware SQL.

6 matches

Geo shard by region in Python

Maps users to database shards based on geographic region with a deterministic hash fallback.

import json
from collections import defaultdict

REGION_SHARD_MAP = {
    "na": ["shard-01", "shard-02"],
    "eu": ["shard-03", "shard-04", "shard-05"],
    "ap": ["shard-06"],
    "sa": ["shard-07", "shard-08"],
}

# user_id -> region (mock lookup)
USER_REGIONS = {
    "u_1001": "na",
    "u_1002": "eu",
    "u_1003…

13 0 Open

Database scaling & optimization easy

How to Mock Date Sharding by Range in Python

Split a date interval into fixed-size contiguous shards, returning each window as an ISO date string pair.

date datetime sharding

Python

from datetime import date, timedelta

def shard_ranges(start_date, end_date, shard_days=7):
    if start_date > end_date:
        raise ValueError("start_date cannot be after end_date")

    shards = []
    current = start_date
    while current <= end_date:
        shard_end = min(current + timedelta(days=shard_days …

13 0 Open

Database scaling & optimization easy

How to Replicate Data Across All Shards in Python

Mocks a global table that replicates a key-value pair to every shard, ensuring reads return the same value from any shard.

sharding replication distributed systems

Python

from dataclasses import dataclass
from typing import Dict, List


@dataclass
class Shard:
    id: str
    data: Dict[str, int]


class GlobalTable:
    def __init__(self, shards: List[Shard]):
        self._shards = {s.id: s for s in shards}

    def set_value(self, key: str, value: int) -> None:
        """Replicate …

14 0 Open

Database scaling & optimization easy

How to Shard Data by User ID Hash in Python

Deterministically map user IDs to shard indexes using an MD5 hash modulo the shard count in Python.

sharding hashing md5

Python

import hashlib

def shard_id(user_id: str, num_shards: int = 4) -> int:
    """Deterministically map a user_id to a shard index using MD5."""
    digest = hashlib.md5(user_id.encode("utf-8")).hexdigest()
    return int(digest[:8], 16) % num_shards

if __name__ == "__main__":
    user_ids = ["alice", "bob", "carol", "d…

12 0 Open

Database scaling & optimization easy

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.

sharding hash partitioning

Python

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


…

14 0 Open

Database scaling & optimization easy

Rebalance Shard Ranges Across Nodes in Python

A mock rebalancing function that shuffles shard ranges and distributes them evenly across nodes using round-robin assignment.

sharding rebalancing dataclass

Python

import random
from dataclasses import dataclass

@dataclass
class Shard:
    id: int
    start: int
    end: int

def rebalance_shards(shards: list[Shard], node_count: int) -> dict[int, list[Shard]]:
    """Mock rebalancing of shard ranges across nodes."""
    all_ranges = [(s.start, s.end) for s in shards]
    random…

11 0 Open

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