Qdrant

🔟 Basic Questions to Understand Qdrant and Vector Databases

  1. What is a vector database, and how is it different from a traditional relational database?

  2. What are embeddings, and why are they important in vector databases?

  3. What is Qdrant, and what makes it suitable for vector similarity search?

  4. How does Qdrant store and organize vector data internally?

  5. What is Approximate Nearest Neighbor (ANN) search, and how does Qdrant implement it?

  6. How do you insert (upsert) vector data into Qdrant, and what is a collection?

  7. How does Qdrant handle metadata filtering along with vector search?

  8. What are some common use cases of Qdrant (e.g., semantic search, recommendation systems, etc.)?

  9. How can Qdrant be integrated with OpenAI, Hugging Face, or other embedding models?

  10. What are the deployment options for Qdrant (self-hosted, Docker, cloud)?


Perfect! Here’s an easy-to-understand breakdown of those 10 basic questions with beginner-friendly answers and some practical examples where needed:


1. What is a vector database, and how is it different from a traditional relational database?

A vector database stores and searches high-dimensional vectors (embeddings) rather than rows and columns like traditional relational databases (e.g., MySQL).

  • Traditional DB: name = 'Ivy', age = 27

  • Vector DB: embedding = [0.25, -0.91, 0.03, ..., 0.67] (e.g., a 768-dimensional vector)

➡️ Used for: Searching semantic meaning, not exact values.


2. What are embeddings, and why are they important in vector databases?

Embeddings are numerical representations of data (text, images, etc.) created using AI models. They help machines understand the semantic meaning of content.

  • Example:

    • "dog" → [0.1, 0.7, ...]

    • "puppy" → similar vector

    • "car" → very different vector

➡️ These embeddings are what you store in a vector DB like Qdrant for similarity search.


Qdrant is an open-source vector search engine built for real-time, efficient, and scalable semantic search.

✅ Key strengths:

  • Fast ANN (Approximate Nearest Neighbor) search

  • Rich metadata filtering

  • REST & gRPC APIs

  • Integration with Python, JS, etc.


4. How does Qdrant store and organize vector data internally?

Qdrant organizes data into collections. Each collection holds:

  • Vectors

  • Optional metadata (payload)

  • Optional vector names if you use multiple embeddings per record

Structure example:


5. What is Approximate Nearest Neighbor (ANN) search, and how does Qdrant implement it?

ANN search finds "close enough" vectors without scanning everything, making it super fast.

Qdrant uses HNSW (Hierarchical Navigable Small World graphs) – a fast and accurate graph-based algorithm to find similar vectors quickly.

➡️ Think of it like GPS for ideas: "find me texts close in meaning to this one."


6. How do you insert (upsert) vector data into Qdrant, and what is a collection?

To insert data:

  • Create a collection first.

  • Use the upsert API to insert vectors with optional metadata.

Example:


You can filter by metadata (payload) while doing similarity search.

Example:

"Find similar documents about AI that are also tagged legaltech"


8. What are some common use cases of Qdrant?

  • Semantic Search: Search by meaning instead of keyword.

  • Recommendation Engines: "You might also like…" based on vector similarity.

  • Chatbots / RAG: Retrieve relevant info from a vector DB to answer user questions.

  • Image / Video Search: Find visually similar items.


9. How can Qdrant be integrated with OpenAI, Hugging Face, or other embedding models?

✅ Common flow:

  1. Use OpenAI or Hugging Face to convert text → embeddings.

  2. Store them in Qdrant.

  3. At query time, embed the query → search → return top similar results.

Example using OpenAI:


10. What are the deployment options for Qdrant (self-hosted, Docker, cloud)?

You can run Qdrant:

  • Self-hosted (on your server)

  • Docker (most popular)

  • Qdrant Cloud (managed service)

➡️ Ideal for fast prototyping: docker run -p 6333:6333 qdrant/qdrant


Awesome! Let’s walk through a simple example using OpenAI embeddings + Qdrant with Python. We’ll simulate a basic semantic search system, like searching through documents or FAQs.


🧪 Use Case: Semantic Search with OpenAI + Qdrant

Goal: You want to store text data (like FAQ answers or article snippets), embed them using OpenAI, store in Qdrant, and search semantically.


✅ Prerequisites

Install these:


⚙️ Step 1: Setup OpenAI + Qdrant Clients


📌 Step 2: Add Some Text Data

Let’s embed 3 small docs using OpenAI and store them.


Now, let’s query something similar in meaning (but phrased differently).


📦 Output Example


🔁 Bonus: Add Metadata Filtering

Add tags to payloads:

Then filter on them:


Nice! Since you're interested in FastAPI + Jinja + PDF + Qdrant + OpenAI, I’ll guide you through building a mini web app that:


🧩 Use Case: Upload PDFs → Extract & Embed Content → Store in Qdrant → Semantic Search via UI


🛠️ Tech Stack:

  • FastAPI – web backend

  • Jinja2 – HTML templating

  • PyMuPDF – for PDF text extraction

  • OpenAI – for generating embeddings

  • Qdrant – for vector search

  • Weaviate alternative – using Qdrant instead


🔧 Step-by-step Architecture:

  1. 📄 Upload PDF(s) via a Jinja-based form

  2. 📤 Extract text from each PDF (via fitz)

  3. 🧠 Convert text to embeddings using OpenAI

  4. 🧊 Store embeddings in Qdrant with metadata

  5. 🔍 Accept search queries and return semantically similar chunks


Awesome! I’ve created your core FastAPI app with Jinja2 frontend support to handle:

  • ✅ PDF uploads

  • ✅ Text chunk extraction

  • ✅ OpenAI embedding

  • ✅ Storing vectors in Qdrant

  • ✅ Semantic search with user queries

🗂️ You’ll need:

1. A templates/index.html file:

Would you like me to generate that next (with file upload, search form, and results display)?

2. Local Qdrant running:

3. requirements.txt:

Let me know if you'd like:

  • The index.html UI template,

  • Deployment instructions (e.g., Docker, Render),

  • Or any API key handling tips (e.g., dotenv).


Docker compose

Here you go!


🖼️ templates/index.html

Create a folder named templates/ and add this file inside it:


🐳 docker-compose.yml

Here’s a simple docker-compose.yml file to run both your FastAPI app and Qdrant:


🐍 Dockerfile

Add this to your root folder to build your FastAPI app container:


📦 requirements.txt


✅ Next Steps

  1. Add your .env file (or replace the OPENAI_API_KEY in docker-compose.yml)

  2. Build and run:

Visit: http://localhost:8000


Great! Focusing on collections and points (not pointers 😉) in Qdrant is a smart move—these are the building blocks of how data is stored and searched. Let’s break them down clearly:


📚 1. What is a Collection in Qdrant?

A collection in Qdrant is like a table in a relational database.

Each collection:

  • Holds a group of vectors

  • Has a specific vector size (e.g., 1536 for OpenAI)

  • Uses a particular distance metric (Cosine, Dot, Euclidean)

  • Can include payloads (i.e., metadata like titles, tags, etc.)

✅ Example:

➡️ This sets up a collection to store vectors of length 1536 and use cosine similarity.


📍 2. What is a Point in Qdrant?

A point is a single item stored in a collection. Think of it as a row in a database table.

Each point has:

  • A unique ID (can be int or UUID string)

  • A vector

  • An optional payload (metadata)

✅ Point Example:

You can insert/update a point using upsert:


🔄 3. How Do You Update Points?

Use the same upsert function. If the point id already exists, it updates the vector and payload.

Want to update only payload?


❌ 4. How to Delete Points or Collections?

Delete a specific point:

Delete a whole collection:


🎯 5. Search in a Collection

You always search within a collection. Here's how:

You can also filter by payload:


🛠️ Common Qdrant Terms Recap

Term
Meaning

Collection

A named group of vectors (like a table)

Point

A vector + payload + ID (like a row)

Payload

Metadata attached to a point

Upsert

Insert or update a point

Vector

Embedding used for similarity search

Distance

Similarity function (Cosine, Dot, etc.)


Would you like me to generate code examples to:

  • Handle multiple collections (e.g., per user or file)?

  • Add namespaces or filters for search?

  • Automatically check if a collection exists before creating?

Let me know where you want to go deeper 🔍


Yes, you absolutely can put multiple users’ embeddings into a single collection in Qdrant — and it’s actually a common pattern in many applications like:

  • Multi-user semantic search

  • Multi-tenant apps

  • Chatbots with shared backends

But how you do it matters, especially if you want to isolate or query them per user.


Store all embeddings in one collection, and use the payload to differentiate users.

Example: Two users uploading documents


You can filter by user_id so each user only sees their own data:


🛡️ Why This is Better than One Collection per User:

Option
Pros
Cons

🟢 One collection

Easier to manage, query, and scale

Must filter carefully by user_id

🔴 One collection per user

Isolation is strong

Hard to scale, hard to query across users

If you're building a multi-user app (like a SaaS product), one collection with user_id filtering is the best practice.


Would you like a FastAPI endpoint that adds this logic for per-user document upload and search?


Absolutely! Let’s take a deeper yet beginner-friendly dive into the core concepts of Qdrant: collection, point, payload, upsert, vector, distance – these form the backbone of vector search engines.


📁 1. Collection

A collection is like a “folder” or “table” where related vectors are stored.

🔹 Key Facts:

  • Each collection has:

    • A name (like "pdf_chunks" or "user_documents")

    • A vector size (e.g. 768 or 1536)

    • A distance function (how similarity is measured)

🧠 Analogy:

If Qdrant is a library, each collection is a bookshelf. All books on that shelf are sorted by a common theme (vector size + similarity logic).


📍 2. Point

A point is a single item (row) in a collection — it holds a vector + optional metadata (payload) + a unique ID.

🔹 Structure:

🧠 Analogy:

A point is like a book in a bookshelf. It has:

  • A unique ID (like a barcode)

  • Contents (vector)

  • Info on the back cover (payload)


🧾 3. Payload

The payload is the extra metadata you attach to a point — it’s not part of the vector but helps you filter or organize results.

🔹 Use it for:

  • User IDs

  • Tags

  • Sources (e.g., PDF name)

  • Timestamps

  • Categories

🔍 Use case:

“Search semantically for answers, but only from user_1’s files

You filter by this:


🔁 4. Upsert

Upsert = “insert if new, update if exists”

You use it to add or update points in a collection.

✅ Example:

If "faq-001" already exists, it updates the vector and payload.


📐 5. Vector

A vector is a list of numbers that represents the meaning of some content (like a sentence or image).

🔹 Example:

Vectors come from embedding models like:

  • OpenAI’s text-embedding-3-small

  • Hugging Face Transformers

  • Cohere, etc.

🧠 Why Use Vectors?

Because they capture meaning, not just keywords. You can now ask:

“Which document is most semantically similar to this question?”


📏 6. Distance

A distance function is how Qdrant measures how similar two vectors are.

Options:

  • Cosine – angle between vectors (great for NLP)

  • Dot – dot product (works well with normalized vectors)

  • Euclidean – physical distance (L2 norm)

🔍 Cosine Similarity Example:

🧠 Tip:

  • For OpenAI embeddings → use Cosine

  • For image search → often Euclidean


🔄 Summary Table

Concept
What it is
Analogy

Collection

A group of related vectors

A bookshelf

Point

A single record with vector + metadata

A book

Payload

Metadata for filtering/search context

Book info on the back cover

Upsert

Insert or update a point

Add or replace a book

Vector

Numeric representation of meaning

Encoded essence of the content

Distance

How similarity is measured

Angle or distance between books

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