Add missing benchmarks (#37)

README.md

@@ -20,7 +20,7 @@ Exporting to CSV has the same pitfalls as loading from CSV, and sometimes even c
 Since Postgres does not natively support loading from Parquet this library provides an io-free encoder that can convert from Parquet to Postgres' binary format on the fly.
 It accepts Arrow data as an input which means great support for reading Parquet files from all sorts of sources (disk, HTTP, object stores, etc.) in an efficient and performant manner.
 
-Benchmarks using the NYC Yellow Cab dataset show that it takes `pgpq` [less than 1 second to encode 1M rows](py/benches/encode.ipynb) and that the [cost of encoding + binary copy is lower than the cost of a native CSV copy](py/benches/encode.ipynb) (which ignores the cost of a CSV export if the data was a Parquet file in the first place).
+Benchmarks using the NYC Yellow Cab dataset show that it takes `pgpq` [less than 1 second to encode 1M rows](py/benches/encode.ipynb) and that the [cost of encoding + binary copy is lower than the cost of a native CSV copy](py/benches/copy.ipynb) (which ignores the cost of a CSV export if the data was a Parquet file in the first place).
 
 ## Python distribution
 

py/benches/copy.ipynb

@@ -0,0 +1,198 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import pyarrow.parquet as pq\n",
+    "from pyarrow.csv import write_csv\n",
+    "from pgpq import ArrowToPostgresBinaryEncoder"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from pathlib import Path\n",
+    "import requests\n",
+    "\n",
+    "file = Path(\".\").resolve().parent.parent / \"yellow_tripdata_2022-01.parquet\"\n",
+    "if not file.exists():\n",
+    "    with requests.get(\"https://d37ci6vzurychx.cloudfront.net/trip-data/yellow_tripdata_2022-01.parquet\", stream=True) as r:\n",
+    "        r.raise_for_status()\n",
+    "        with file.open(\"wb\") as f:\n",
+    "            for chunk in r.iter_content(chunk_size=1024 * 1024):\n",
+    "                f.write(chunk)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "arrow_table = pq.read_table(file)\n",
+    "\n",
+    "csv_file = file.with_suffix(\".csv\")\n",
+    "binary_file = file.with_suffix(\".bin\")\n",
+    "\n",
+    "write_csv(arrow_table, csv_file)\n",
+    "\n",
+    "def encode_file():\n",
+    "    encoder = ArrowToPostgresBinaryEncoder(arrow_table.schema)\n",
+    "    with binary_file.open(\"wb\") as f:\n",
+    "        f.write(encoder.write_header())\n",
+    "        for batch in arrow_table.to_batches():\n",
+    "            f.write(encoder.write_batch(batch))\n",
+    "        f.write(encoder.finish())\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "fbc6a0c8379d4971b058a9cd4fa45677",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "FloatProgress(value=0.0, layout=Layout(width='auto'), style=ProgressStyle(bar_color='black'))"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "DuckDB (python): 2.92\n",
+      "COPY 2463931\n",
+      "CSV (psql): 6.10\n",
+      "COPY 2463931\n",
+      "Binary (psql): 3.39\n",
+      "Binary (python): 2.47\n"
+     ]
+    }
+   ],
+   "source": [
+    "import subprocess\n",
+    "from time import time\n",
+    "import psycopg\n",
+    "import duckdb\n",
+    "\n",
+    "# run via docker run -it -e POSTGRES_PASSWORD=postgres -p 5432:5432 postgres\n",
+    "# on an M1 Max MacBook Pro\n",
+    "# with 10 CPU and 8GB of RAM as per Docker Desktop settings \n",
+    "dsn = 'postgresql://postgres:postgres@localhost/postgres'\n",
+    "\n",
+    "\n",
+    "with psycopg.connect(dsn) as conn:\n",
+    "    with conn.cursor() as cursor:\n",
+    "        cursor.execute(\"DROP TABLE IF EXISTS data\")\n",
+    "        encoder = ArrowToPostgresBinaryEncoder(arrow_table.schema)\n",
+    "        pg_schema = encoder.schema()\n",
+    "        cols = [f'\"{col_name}\" {col.data_type.ddl()}' for col_name, col in pg_schema.columns]\n",
+    "        ddl = f\"CREATE TABLE data ({','.join(cols)})\"\n",
+    "        cursor.execute(ddl)  # type: ignore\n",
+    "        conn.commit()\n",
+    "\n",
+    "\n",
+    "def clean():\n",
+    "    with psycopg.connect(dsn) as conn:\n",
+    "        conn.autocommit = True\n",
+    "        with conn.cursor() as cursor:\n",
+    "            cursor.execute(\"TRUNCATE TABLE data\")\n",
+    "            cursor.execute(\"VACUUM data\")\n",
+    "\n",
+    "\n",
+    "def copy_as_csv() -> float:\n",
+    "    start = time()\n",
+    "    subprocess.run([\"psql\", dsn, \"-c\", f\"\\\\copy data FROM '{csv_file}' WITH (FORMAT CSV, HEADER);\"], check=True)\n",
+    "    return time()-start\n",
+    "\n",
+    "\n",
+    "def copy_as_binary_psql() -> float:\n",
+    "    start = time()\n",
+    "    encode_file()\n",
+    "    subprocess.run([\"psql\", dsn, \"-c\", f\"\\\\copy data FROM '{binary_file}' WITH (FORMAT BINARY);\"], check=True)\n",
+    "    return time()-start\n",
+    "\n",
+    "\n",
+    "def copy_as_binary_python() -> float:\n",
+    "    with psycopg.connect(dsn) as conn:\n",
+    "        conn.autocommit = True\n",
+    "        with conn.cursor() as cursor:\n",
+    "            start = time()\n",
+    "            # read the table to be fair to the other methods which are reading from disk\n",
+    "            arrow_table = pq.read_table(file)\n",
+    "            encoder = ArrowToPostgresBinaryEncoder(arrow_table.schema)\n",
+    "            with cursor.copy(\"COPY data FROM STDIN WITH (FORMAT BINARY)\") as copy:\n",
+    "                copy.write(encoder.write_header())\n",
+    "                for batch in arrow_table.to_batches():\n",
+    "                    copy.write(encoder.write_batch(batch))\n",
+    "                copy.write(encoder.finish())\n",
+    "    return time()-start\n",
+    "\n",
+    "\n",
+    "def copy_via_duckdb() -> float:\n",
+    "    clean()\n",
+    "    start = time()\n",
+    "    duckdb.sql(\n",
+    "        \"INSTALL postgres;\"\n",
+    "        \"ATTACH 'postgresql://postgres:postgres@localhost/postgres' AS pg (TYPE postgres);\"\n",
+    "        f\"INSERT INTO pg.data SELECT * FROM '{file.resolve().absolute()}';\"\n",
+    "    )\n",
+    "    return time()-start\n",
+    "\n",
+    "\n",
+    "clean()\n",
+    "print(f\"DuckDB (python): {copy_via_duckdb():.2f}\")\n",
+    "\n",
+    "# psql is the \"gold standard\" so it's worth comparing to it\n",
+    "clean()\n",
+    "print(f\"CSV (psql): {copy_as_csv():.2f}\")\n",
+    "\n",
+    "clean()\n",
+    "print(f\"Binary (psql): {copy_as_binary_psql():.2f}\")\n",
+    "\n",
+    "clean()\n",
+    "print(f\"Binary (python): {copy_as_binary_python():.2f}\")"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": ".venv",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.12.1"
+  },
+  "vscode": {
+   "interpreter": {
+    "hash": "bfe9facd2a803056c7d94beaa559586e38ec822d68c7c39f2e0c752e8e6533cf"
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}

py/pyproject.toml

@@ -34,7 +34,8 @@ test = [
 ]
 bench = [
   "jupyter >=1.0.0",
-  "requests"
+  "requests",
+  "duckdb",
 ]
 
 [project.urls]