main.go

// Licensed to ClickHouse, Inc. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. ClickHouse, Inc. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package main

import (
	"database/sql"
	"fmt"
	"log"
	"time"

	_ "github.com/ClickHouse/clickhouse-go/v2"
)

func benchmarkRead(conn *sql.DB) error {
	rows, err := conn.Query(`
SELECT
	number
	, randomString(25)
	, array(1, 2, 3, 4, 5)
	, now()
FROM system.numbers LIMIT 1000000
`)
	if err != nil {
		return err
	}
	for rows.Next() {
		var (
			col1 uint64
			col2 string
			col3 []uint8
			col4 time.Time
		)
		if err := rows.Scan(&col1, &col2, &col3, &col4); err != nil {
			return err
		}
	}
	return nil
}

func benchmarkString(conn *sql.DB) error {
	rows, err := conn.Query(`SELECT toString(number) FROM numbers(500000000)`)
	if err != nil {
		return err
	}
	for rows.Next() {
		var (
			col1 string
		)
		if err := rows.Scan(&col1); err != nil {
			return err
		}
	}
	return nil
}

func main() {
	conn, err := sql.Open("clickhouse", "clickhouse://127.0.0.1:9000")
	if err != nil {
		log.Fatal(err)
	}
	start := time.Now()
	if err := benchmarkRead(conn); err != nil {
		log.Fatal(err)
	}
	fmt.Printf("benchmarkRead: %v\n", time.Since(start))
	start = time.Now()
	if err := benchmarkString(conn); err != nil {
		log.Fatal(err)
	}
	fmt.Printf("benchmarkString: %v\n", time.Since(start))
}