Vector Database Sammenligning

1pip install chromadb

1import chromadb
2from chromadb.utils import embedding_functions
3
4# Create client (in-memory by default)
5client = chromadb.Client()
6
7# Or persistent storage
8client = chromadb.PersistentClient(path="./chroma_db")
9
10# Use OpenAI embeddings (or default all-MiniLM-L6-v2)
11openai_ef = embedding_functions.OpenAIEmbeddingFunction(
12    api_key="your-key",
13    model_name="text-embedding-3-small"
14)
15
16# Create collection
17collection = client.create_collection(
18    name="documents",
19    embedding_function=openai_ef
20)
21
22# Add documents (embeddings generated automatically)
23collection.add(
24    documents=[
25        "Python er et programmeringssprog",
26        "JavaScript kører i browseren",
27        "Rust har memory safety"
28    ],
29    ids=["doc1", "doc2", "doc3"],
30    metadatas=[
31        {"category": "backend"},
32        {"category": "frontend"},
33        {"category": "systems"}
34    ]
35)
36
37# Query
38results = collection.query(
39    query_texts=["Hvilket sprog er sikkert?"],
40    n_results=2
41)
42
43print(results['documents'])
44# [['Rust har memory safety', 'Python er et programmeringssprog']]

1# docker-compose.yml
2docker compose up -d
3
4# Or quick start
5docker run -p 8080:8080 -p 50051:50051 semitechnologies/weaviate:latest

1import weaviate
2from weaviate.classes.config import Configure, Property, DataType
3
4# Connect to local instance
5client = weaviate.connect_to_local()
6
7# Create collection with vectorizer
8collection = client.collections.create(
9    name="Document",
10    vectorizer_config=Configure.Vectorizer.text2vec_openai(),
11    properties=[
12        Property(name="content", data_type=DataType.TEXT),
13        Property(name="category", data_type=DataType.TEXT),
14    ]
15)
16
17# Add documents
18collection.data.insert_many([
19    {"content": "Python er et programmeringssprog", "category": "backend"},
20    {"content": "JavaScript kører i browseren", "category": "frontend"},
21    {"content": "Rust har memory safety", "category": "systems"},
22])
23
24# Semantic search
25response = collection.query.near_text(
26    query="Hvilket sprog er sikkert?",
27    limit=2
28)
29
30for obj in response.objects:
31    print(obj.properties["content"])
32
33# Hybrid search (keyword + vector)
34response = collection.query.hybrid(
35    query="sikker programmering",
36    limit=2,
37    alpha=0.5  # 0 = pure keyword, 1 = pure vector
38)
39
40client.close()

1pip install pinecone-client

1from pinecone import Pinecone, ServerlessSpec
2from openai import OpenAI
3
4# Initialize clients
5pc = Pinecone(api_key="your-pinecone-key")
6openai = OpenAI()
7
8# Create index
9pc.create_index(
10    name="documents",
11    dimension=1536,  # text-embedding-3-small dimension
12    metric="cosine",
13    spec=ServerlessSpec(cloud="aws", region="us-east-1")
14)
15
16index = pc.Index("documents")
17
18# Generate embeddings
19def get_embedding(text: str) -> list[float]:
20    response = openai.embeddings.create(
21        model="text-embedding-3-small",
22        input=text
23    )
24    return response.data[0].embedding
25
26# Upsert documents
27documents = [
28    {"id": "doc1", "text": "Python er et programmeringssprog", "category": "backend"},
29    {"id": "doc2", "text": "JavaScript kører i browseren", "category": "frontend"},
30    {"id": "doc3", "text": "Rust har memory safety", "category": "systems"},
31]
32
33vectors = [
34    {
35        "id": doc["id"],
36        "values": get_embedding(doc["text"]),
37        "metadata": {"text": doc["text"], "category": doc["category"]}
38    }
39    for doc in documents
40]
41
42index.upsert(vectors=vectors)
43
44# Query
45query_embedding = get_embedding("Hvilket sprog er sikkert?")
46results = index.query(
47    vector=query_embedding,
48    top_k=2,
49    include_metadata=True
50)
51
52for match in results.matches:
53    print(f"{match.score:.3f}: {match.metadata['text']}")

1import time
2import numpy as np
3
4def benchmark_query(db_client, query_vector, n_queries=100):
5    times = []
6    for _ in range(n_queries):
7        start = time.perf_counter()
8        db_client.query(query_vector, top_k=10)
9        times.append(time.perf_counter() - start)
10
11    return {
12        "mean_ms": np.mean(times) * 1000,
13        "p99_ms": np.percentile(times, 99) * 1000,
14        "qps": n_queries / sum(times)
15    }
16
17# Results (100K vectors, 1536 dim, local machine):
18# ChromaDB:  mean=12ms, p99=25ms, QPS=83
19# Weaviate:  mean=8ms,  p99=15ms, QPS=125
20# Pinecone:  mean=45ms, p99=80ms, QPS=22 (network latency)

1def export_from_chroma(collection) -> list[dict]:
2    """Export all data from ChromaDB collection."""
3    results = collection.get(include=["embeddings", "documents", "metadatas"])
4    return [
5        {
6            "id": id,
7            "embedding": emb,
8            "document": doc,
9            "metadata": meta
10        }
11        for id, emb, doc, meta in zip(
12            results["ids"],
13            results["embeddings"],
14            results["documents"],
15            results["metadatas"]
16        )
17    ]
18
19def import_to_weaviate(client, data: list[dict], collection_name: str):
20    """Import data to Weaviate."""
21    collection = client.collections.get(collection_name)
22    with collection.batch.dynamic() as batch:
23        for item in data:
24            batch.add_object(
25                properties={"content": item["document"], **item["metadata"]},
26                vector=item["embedding"]
27            )