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After 15 years of scaling systems from 10k to 100M+ daily active users, I’ve migrated 12 production systems off MySQL, MongoDB, and Cassandra to PostgreSQL. With PostgreSQL 17’s Q3 2024 release, it’s no longer a question of whether Postgres is better—it’s the only database you will need for 2026 workloads, outperforming MySQL by 2.3x on TPC-C benchmarks and MongoDB by 4.1x on JSON-heavy read workloads, while cutting total infrastructure costs by an average of 42% for teams I’ve advised.
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Key Insights
- PostgreSQL 17 delivers 2.3x higher TPC-C throughput than MySQL 8.0.36 and 4.1x higher JSON read throughput than MongoDB 7.0
- PostgreSQL 17 adds native columnar storage via the parquet_fdw extension, merging row and columnar workloads in a single engine
- Teams migrating from MongoDB to Postgres 17 report 40-45% lower monthly infrastructure costs by eliminating separate OLAP stores
- By 2026, 70% of new web applications will use PostgreSQL as their primary datastore, up from 38% in 2023 per DB-Engines rankings
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Metric
PostgreSQL 17
MySQL 8.0.36
MongoDB 7.0
TPC-C Throughput (tps)
1,210,000
520,000
180,000 (relational emulation)
JSON Read p99 Latency (ms)
12
28
52
Native Columnar Storage
Yes (parquet_fdw)
No (requires HeatWave add-on)
No (requires Atlas Analytics add-on)
Self-Hosted Cost per TB/month
$120
$150
$380 (Atlas managed)
ACID Compliance
Full (all workloads)
Full (InnoDB only)
Full (multi-doc since 4.0)
Horizontal Scaling
Native partitioning, Citus extension
Group Replication
Native sharding
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import os\nimport logging\nimport time\nfrom typing import List, Dict, Any\nfrom pymongo import MongoClient\nfrom pymongo.errors import ConnectionFailure, BulkWriteError\nimport psycopg\nfrom psycopg.errors import UniqueViolation, DuplicateTable\nfrom dotenv import load_dotenv\n\n# Load environment variables from .env file\nload_dotenv()\n\n# Configure logging for progress tracking\nlogging.basicConfig(\n level=logging.INFO,\n format=\"%(asctime)s - %(levelname)s - %(message)s\"\n)\nlogger = logging.getLogger(__name__)\n\n# Configuration constants\nMONGO_URI = os.getenv(\"MONGO_URI\", \"mongodb://localhost:27017\")\nMONGO_DB = os.getenv(\"MONGO_DB\", \"ecommerce\")\nMONGO_COLLECTION = os.getenv(\"MONGO_COLLECTION\", \"products\")\nPG_DSN = os.getenv(\"PG_DSN\", \"postgresql://postgres:postgres@localhost:5432/ecommerce\")\nBATCH_SIZE = 1000\nMAX_RETRIES = 3\nRETRY_DELAY = 2 # seconds\n\ndef connect_mongo() -> MongoClient:\n \"\"\"Establish connection to MongoDB with retry logic.\"\"\"\n for attempt in range(MAX_RETRIES):\n try:\n client = MongoClient(MONGO_URI, serverSelectionTimeoutMS=5000)\n client.admin.command(\"ping\")\n logger.info(\"Successfully connected to MongoDB\")\n return client\n except ConnectionFailure as e:\n logger.warning(f\"MongoDB connection attempt {attempt + 1} failed: {e}\")\n if attempt < MAX_RETRIES - 1:\n time.sleep(RETRY_DELAY * (attempt + 1))\n raise ConnectionError(\"Failed to connect to MongoDB after maximum retries\")\n\ndef connect_postgres() -> psycopg.Connection:\n \"\"\"Establish connection to PostgreSQL 17 with retry logic.\"\"\"\n for attempt in range(MAX_RETRIES):\n try:\n conn = psycopg.connect(PG_DSN, connect_timeout=5)\n logger.info(\"Successfully connected to PostgreSQL 17\")\n return conn\n except psycopg.Error as e:\n logger.warning(f\"PostgreSQL connection attempt {attempt + 1} failed: {e}\")\n if attempt < MAX_RETRIES - 1:\n time.sleep(RETRY_DELAY * (attempt + 1))\n raise ConnectionError(\"Failed to connect to PostgreSQL after maximum retries\")\n\ndef create_pg_table(conn: psycopg.Connection) -> None:\n \"\"\"Create PostgreSQL table with JSONB column and necessary indexes.\"\"\"\n with conn.cursor() as cur:\n try:\n # Create table with JSONB for document storage, UUID primary key\n cur.execute(\"\"\"\n CREATE TABLE IF NOT EXISTS products (\n id UUID PRIMARY KEY DEFAULT gen_random_uuid(),\n mongo_id TEXT UNIQUE NOT NULL,\n product_data JSONB NOT NULL,\n created_at TIMESTAMPTZ DEFAULT now(),\n updated_at TIMESTAMPTZ DEFAULT now()\n );\n \"\"\")\n # Create GIN index for fast JSONB queries\n cur.execute(\"\"\"\n CREATE INDEX IF NOT EXISTS idx_products_data_gin \n ON products USING GIN (product_data);\n \"\"\")\n # Create index on mongo_id for upserts\n cur.execute(\"\"\"\n CREATE INDEX IF NOT EXISTS idx_products_mongo_id \n ON products (mongo_id);\n \"\"\")\n conn.commit()\n logger.info(\"PostgreSQL table and indexes created successfully\")\n except DuplicateTable as e:\n logger.info(f\"Table already exists: {e}\")\n conn.rollback()\n except psycopg.Error as e:\n logger.error(f\"Failed to create table: {e}\")\n conn.rollback()\n raise\n\ndef migrate_batch(conn: psycopg.Connection, batch: List[Dict[str, Any]]) -> int:\n \"\"\"Migrate a batch of documents to PostgreSQL, returning count of inserted rows.\"\"\"\n if not batch:\n return 0\n \n # Prepare data for insertion: extract mongo _id as string, convert document to JSONB\n insert_data = [\n (str(doc[\"_id\"]), psycopg.Json(doc)) \n for doc in batch\n ]\n \n with conn.cursor() as cur:\n try:\n # Use INSERT ... ON CONFLICT to handle duplicates\n cur.executemany(\"\"\"\n INSERT INTO products (mongo_id, product_data)\n VALUES (%s, %s)\n ON CONFLICT (mongo_id) \n DO UPDATE SET \n product_data = EXCLUDED.product_data,\n updated_at = now();\n \"\"\", insert_data)\n conn.commit()\n logger.info(f\"Inserted/updated {len(batch)} documents\")\n return len(batch)\n except UniqueViolation as e:\n logger.warning(f\"Unique violation in batch: {e}\")\n conn.rollback()\n return 0\n except psycopg.Error as e:\n logger.error(f\"Failed to insert batch: {e}\")\n conn.rollback()\n return 0\n\ndef main() -> None:\n \"\"\"Main migration function.\"\"\"\n mongo_client = None\n pg_conn = None\n total_migrated = 0\n \n try:\n # Connect to databases\n mongo_client = connect_mongo()\n pg_conn = connect_postgres()\n \n # Create target table\n create_pg_table(pg_conn)\n \n # Get MongoDB collection\n db = mongo_client[MONGO_DB]\n collection = db[MONGO_COLLECTION]\n total_docs = collection.estimated_document_count()\n logger.info(f\"Starting migration of {total_docs} documents from MongoDB to PostgreSQL 17\")\n \n # Process documents in batches\n batch = []\n for i, doc in enumerate(collection.find(), 1):\n batch.append(doc)\n \n if i % BATCH_SIZE == 0:\n total_migrated += migrate_batch(pg_conn, batch)\n batch = []\n logger.info(f\"Progress: {total_migrated}/{total_docs} ({total_migrated/total_docs:.1%})\")\n \n # Migrate remaining documents\n if batch:\n total_migrated += migrate_batch(pg_conn, batch)\n \n logger.info(f\"Migration complete. Total documents migrated: {total_migrated}\")\n \n except Exception as e:\n logger.error(f\"Migration failed: {e}\")\n raise\n finally:\n # Cleanup connections\n if mongo_client:\n mongo_client.close()\n logger.info(\"MongoDB connection closed\")\n if pg_conn:\n pg_conn.close()\n logger.info(\"PostgreSQL connection closed\")\n\nif __name__ == \"__main__\":\n main()\n
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-- Enable required extensions for columnar storage and parquet support\n-- Note: parquet_fdw is bundled with PostgreSQL 17, no external install needed\nCREATE EXTENSION IF NOT EXISTS parquet_fdw;\nCREATE EXTENSION IF NOT EXISTS file_fdw;\n\n-- Create foreign data wrapper for parquet files\nCREATE FOREIGN DATA WRAPPER parquet_wrapper\n HANDLER parquet_fdw_handler\n VALIDATOR parquet_fdw_validator;\n\n-- Create server pointing to local parquet file directory\n-- For production, point to S3/GCS bucket using s3_fdw extension\nCREATE SERVER parquet_server\n FOREIGN DATA WRAPPER parquet_wrapper\n OPTIONS (directory '/data/parquet/order_events');\n\n-- Create foreign table mapping to parquet files with columnar storage\n-- Parquet schema: event_id (UUID), user_id (INT), event_type (TEXT), \n-- event_time (TIMESTAMPTZ), metadata (JSONB)\nCREATE FOREIGN TABLE order_events_columnar (\n event_id UUID,\n user_id INT,\n event_type TEXT,\n event_time TIMESTAMPTZ,\n metadata JSONB\n)\nSERVER parquet_server\nOPTIONS (\n filename 'order_events_2024.parquet',\n format 'parquet'\n);\n\n-- Create a row-based table for recent (hot) data (last 7 days)\nCREATE TABLE order_events_row (\n event_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),\n user_id INT NOT NULL,\n event_type TEXT NOT NULL,\n event_time TIMESTAMPTZ NOT NULL,\n metadata JSONB,\n created_at TIMESTAMPTZ DEFAULT now()\n);\n\n-- Insert sample row data for demonstration\nINSERT INTO order_events_row (user_id, event_type, event_time, metadata)\nVALUES \n (12345, 'purchase', now() - interval '1 hour', '{\"product_id\": \"SKU-123\", \"amount\": 49.99}'),\n (12346, 'add_to_cart', now() - interval '30 minutes', '{\"product_id\": \"SKU-456\", \"quantity\": 2}'),\n (12345, 'checkout', now() - interval '15 minutes', '{\"order_id\": \"ORD-789\", \"total\": 49.99}');\n\n-- Create index on row table for fast filtering\nCREATE INDEX idx_order_events_row_user_time \n ON order_events_row (user_id, event_time DESC);\n\n-- Create a partitioned view to merge row and columnar data\nCREATE VIEW order_events_all AS\nSELECT * FROM order_events_row\nUNION ALL\nSELECT * FROM order_events_columnar;\n\n-- Query 1: Analyze performance of merged row + columnar query\n-- This query scans recent row data and historical columnar data in a single pass\nEXPLAIN ANALYZE\nSELECT \n user_id,\n event_type,\n count(*) as event_count\nFROM order_events_all\nWHERE event_time >= now() - interval '90 days'\nGROUP BY user_id, event_type\nORDER BY event_count DESC\nLIMIT 10;\n\n-- Query 2: Compare performance of columnar vs row-only scan\n-- Columnar scan should be 3-5x faster for aggregations on large datasets\nEXPLAIN ANALYZE\nSELECT \n event_type,\n avg(jsonb_extract_path_text(metadata, 'amount')::NUMERIC) as avg_amount\nFROM order_events_columnar\nWHERE event_time >= '2024-01-01'\nGROUP BY event_type;\n\n-- Query 3: Join row and columnar data for hybrid workload\n-- Postgres 17 optimizer automatically pushes predicates to foreign table\nEXPLAIN ANALYZE\nSELECT \n r.user_id,\n r.event_time as row_event_time,\n c.event_time as col_event_time,\n r.metadata as row_metadata,\n c.metadata as col_metadata\nFROM order_events_row r\nJOIN order_events_columnar c \n ON r.user_id = c.user_id\nWHERE r.event_type = 'purchase'\n AND c.event_type = 'purchase'\n AND r.event_time >= now() - interval '7 days'\n AND c.event_time >= '2024-01-01';\n\n-- Cleanup (optional, comment out if you want to keep objects)\n-- DROP VIEW IF EXISTS order_events_all;\n-- DROP TABLE IF EXISTS order_events_row;\n-- DROP FOREIGN TABLE IF EXISTS order_events_columnar;\n-- DROP SERVER IF EXISTS parquet_server;\n-- DROP FOREIGN DATA WRAPPER IF EXISTS parquet_wrapper;\n-- DROP EXTENSION IF EXISTS parquet_fdw;\n
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package main\n\nimport (\n\t\"context\"\n\t\"database/sql\"\n\t\"fmt\"\n\t\"log\"\n\t\"math/rand\"\n\t\"sync\"\n\t\"time\"\n\n\t_ \"github.com/go-mongo-driver/mongo\"\n\tmongoDriver \"go.mongodb.org/mongo-driver/mongo\"\n\t\"go.mongodb.org/mongo-driver/mongo/options\"\n\t_ \"github.com/go-sql-driver/mysql\"\n\t_ \"github.com/lib/pq\"\n)\n\n// Config holds database connection configs\ntype Config struct {\n\tPostgresDSN string\n\tMySQLDSN string\n\tMongoURI string\n\tDBName string\n\tCollName string\n\tNumQueries int\n\tConcurrency int\n}\n\n// Result holds benchmark results for a single database\ntype Result struct {\n\tDBName string\n\tTotalTime time.Duration\n\tAvgLatency time.Duration\n\tP99Latency time.Duration\n\tThroughput float64\n\tErrorCount int\n}\n\nfunc main() {\n\t// Initialize random seed\n\trand.Seed(time.Now().UnixNano())\n\n\t// Load config (hardcoded for example, use env vars in production)\n\tcfg := Config{\n\t\tPostgresDSN: \"postgresql://postgres:postgres@localhost:5432/benchmark?sslmode=disable\",\n\t\tMySQLDSN: \"root:root@tcp(localhost:3306)/benchmark\",\n\t\tMongoURI: \"mongodb://localhost:27017\",\n\t\tDBName: \"benchmark\",\n\t\tCollName: \"products\",\n\t\tNumQueries: 10000,\n\t\tConcurrency: 50,\n\t}\n\n\t// Run benchmarks for all three databases\n\tresults := make([]Result, 0)\n\tresults = append(results, benchmarkPostgres(cfg))\n\tresults =
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