在 Laravel 10.0 使用 pgvector 向量搜尋操作 PostgreSQL 資料庫

Laravel
, , , , , ,

建立專案

建立專案。

1
laravel new pgvector-laravel

建立資料庫。

1
docker run -it -d --name pgvector -v pgvector-data:/var/lib/postgresql/data -e POSTGRES_PASSWORD=password -e POSTGRES_USER=forge --publish 5432:5432 ankane/pgvector

安裝套件。

1
composer require ankane/pgvector

發布相關資源。

1
php artisan vendor:publish --tag="pgvector-migrations"

修改 .env 檔。

1
2
3
4
5
6
DB_CONNECTION=pgsql
DB_HOST=127.0.0.1
DB_PORT=5432
DB_DATABASE=forge
DB_USERNAME=forge
DB_PASSWORD=password

執行遷移。

1
php artisan migrate

建立模型

建立一個 Embedding 模型。

1
php artisan make:model Embedding -m

修改 database/migrations/..._create_embeddings_table.php 檔。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        Schema::create('embeddings', function (Blueprint $table) {
            $table->id();
            $table->vector('embedding', 1536); // Dimensionality; 1536 for OpenAI's ada-002
            $table->json('metadata');
            $table->timestamps();
        });

        // This is a Postgres-specific index that allows us to do fast nearest-neighbor searches
        // when there are a lot of high-dimensional embeddings in the database.
        DB::statement('CREATE INDEX embedding_index ON embeddings USING ivfflat (embedding vector_l2_ops) WITH (lists = 100)');
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        Schema::dropIfExists('embeddings');
    }
};

修改 app/Models/Embedding.php 檔。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Pgvector\Laravel\Vector;

class Embedding extends Model
{
    use HasFactory;

    protected $fillable = [
        'embedding',
        'metadata',
    ];

    protected $casts = [
        'embedding' => Vector::class,
        'metadata' => 'array',
    ];
}

執行遷移。

1
php artisan migrate

建立範例指令

安裝 OpenAI SDK 套件。

1
2
composer require openai-php/laravel
php artisan vendor:publish --provider="OpenAI\Laravel\ServiceProvider"

修改 .env 檔，添加 OpenAI 的 API Key。

1
OPENAI_API_KEY=sk-...

建立資料

修改 routes/console.php 檔，建立 insert 範例指令。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
<?php

use App\Models\Embedding;
use Illuminate\Support\Facades\Artisan;
use OpenAI\Laravel\Facades\OpenAI;

Artisan::command('insert', function() {
    $sayings = [
        'Felines say meow',
        'Canines say woof',
        'Birds say tweet',
        'Humans say hello',
    ];

    $result = OpenAI::embeddings()->create([
        'model' => 'text-embedding-ada-002',
        'input' => $sayings
    ]);

    foreach ($sayings as $key=>$saying) {
        Embedding::query()->create([
            'embedding' => $result->embeddings[$key]->embedding,
            'metadata' => [
                'saying' => $saying,
            ]
        ]);
    }
});

執行 insert 指令。

1
php artisan insert

檢查紀錄。

1
2
3
4
5
6
7
8
docker exec -it \
    pgvector \
    psql -U forge -d forge -c "select count(*) from embeddings"

count
-------
     4
(1 row)

查詢資料

修改 routes/console.php 檔，建立 search 範例指令。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
<?php

use App\Models\Embedding;
use Illuminate\Support\Facades\Artisan;
use OpenAI\Laravel\Facades\OpenAI;
use Pgvector\Laravel\Vector;

// ...

Artisan::command('search', function() {
    $result = OpenAI::embeddings()->create([
        'model' => 'text-embedding-ada-002',
        'input' => 'What do dogs say?',
    ]);

    $embedding = new Vector($result->embeddings[0]->embedding);

    $this->table(
        ['saying'],
        Embedding::query()
            ->orderByRaw('embedding <-> ?', [$embedding])
            ->take(2)
            ->pluck('metadata')
    );
});

執行 search 指令。

1
2
3
4
5
6
7
8
php artisan search

+------------------+
| saying           |
+------------------+
| Canines say woof |
| Felines say meow |
+------------------+

程式碼

參考資料