save embeddings as BLOB in MySQL with Node.js

save-embeddings-as-BLOB-in-MySQL.js

import { createPool } from 'mysql2/promise'
import 'dotenv/config'

const pool = createPool({
  host: process.env.DB_HOST,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  database: process.env.DB_DATABASE,
  waitForConnections: true,
  connectionLimit: 5,
  idleTimeout: 10000, // idle connections timeout, in milliseconds, the default value 60000
  queueLimit: 10 // 0 means no limit for queue length
});

async function main() {
  try {
    const embeddings = [0.6, 0.8];
    
    // save embeddings as BLOB into the example_table
    const arr = Float32Array.from(embeddings);
    const buf = Buffer.from(arr.buffer, arr.byteOffset, arr.byteLength);
    let [result] = await pool.execute('INSERT INTO example_table (embeddings) VALUES (?)', [buf]);
    const id = result.insertId;
    
    // read back embeddings from the table
    let [rows] = await pool.execute('SELECT * FROM example_table WHERE id = ?', [id]);
    const buf2 = rows[0].embeddings; // buf2 is a Buffer; Buffer can be treated as Uint8Array for most purposes
    const arr2 = new Float32Array(buf2.buffer, buf2.byteOffset, Math.floor(buf2.length/Float32Array.BYTES_PER_ELEMENT));
  } catch(e) {
    console.log(e)
  } finally {
    await pool.end();    
  }
}

main()