What is the largest database project you have implemented or maintained?

In one of my Go projects, I worked with an order management system where the database contained about 10 million records. PostgreSQL was used with sharding based on geographic location to distribute the load. The main tasks included query optimization, index tuning, and working with transactions to ensure data integrity.

Example of connecting to the database and executing a query in Go:

import (
    "database/sql"
    _ "github.com/lib/pq"
    "log"
)

func getOrderById(db *sql.DB, id int) (string, error) {
    var orderInfo string
    err := db.QueryRow("SELECT info FROM orders WHERE id = $1", id).Scan(&orderInfo)
    if err != nil {
        return "", err
    }
    return orderInfo, nil
}