Google Vertex AI Vector Search v2.0

This notebook demonstrates how to use Vertex AI Vector Search v2.0 with LlamaIndex.

Vertex AI Vector Search v2.0 introduces a simplified collection-based architecture that eliminates the need for separate index creation and endpoint deployment.

v2.0 vs v1.0

Feature	v1.0	v2.0
Architecture	Index + Endpoint	Collection
Setup Steps	Create index → Deploy to endpoint	Create collection
GCS Bucket	Required for batch updates	Not needed
Hybrid Search	Not supported	Supported

Note: For v1.0 usage, see VertexAIVectorSearchDemo.ipynb

Install Dependencies

Install LlamaIndex with v2 support:

Note: V2 support requires llama-index-vector-stores-vertexaivectorsearch version that supports Vertex AI Vector Search v2.0 API.

python

# Install with v2 support (the [v2] extra installs google-cloud-vectorsearch)
# !pip install 'llama-index-vector-stores-vertexaivectorsearch[v2]' llama-index-embeddings-vertex llama-index-llms-vertex

Authentication (if using Colab):

python

# Colab authentication.
import sys

if "google.colab" in sys.modules:
    from google.colab import auth

    auth.authenticate_user()
    print("Authenticated")

Configuration

Set your Google Cloud project details:

python

# Google Cloud Configuration
PROJECT_ID = "your-project-id"  # @param {type:"string"}
REGION = "us-central1"  # @param {type:"string"}
COLLECTION_ID = "llamaindex-demo-collection"  # @param {type:"string"}

# Embedding dimensions (768 for text-embedding-004)
EMBEDDING_DIMENSION = 768

Create a v2 Collection

Unlike v1.0 which requires creating an index and deploying it to an endpoint, v2.0 only requires creating a collection.

Important for Hybrid Search: The collection schema below is configured to support all hybrid search features:

Text Search: String fields (text, category, color) can be searched with keywords
Semantic Search: The vertex_embedding_config enables auto-embeddings for SEMANTIC_HYBRID mode
Filtering: Numeric (price) and string fields support metadata filtering

python

from google.cloud import vectorsearch_v1beta

# Initialize the client
client = vectorsearch_v1beta.VectorSearchServiceClient()

# Check if collection already exists
parent = f"projects/{PROJECT_ID}/locations/{REGION}"
collection_name = f"{parent}/collections/{COLLECTION_ID}"

# Collection schema that supports:
# - Dense vector search (embedding field)
# - Text search on text, category, color fields (for HYBRID mode)
# - Semantic search with auto-embeddings (for SEMANTIC_HYBRID mode)
# - Filtering on price, category, color fields
collection_config = {
    "data_schema": {
        "type": "object",
        "properties": {
            "text": {"type": "string"},  # Main text content (searchable)
            "ref_doc_id": {"type": "string"},  # Document reference
            "price": {"type": "number"},  # Filterable numeric field
            "color": {"type": "string"},  # Filterable/searchable string
            "category": {"type": "string"},  # Filterable/searchable string
        },
    },
    "vector_schema": {
        "embedding": {
            "dense_vector": {
                "dimensions": EMBEDDING_DIMENSION,
                # Auto-embedding config enables SEMANTIC_HYBRID mode
                # Vertex AI will auto-generate embeddings for semantic search
                "vertex_embedding_config": {
                    "model_id": "text-embedding-004",
                    "text_template": "{text}",
                    "task_type": "RETRIEVAL_DOCUMENT",
                },
            }
        },
    },
}

try:
    request = vectorsearch_v1beta.GetCollectionRequest(name=collection_name)
    collection = client.get_collection(request=request)
    print(f"Collection already exists: {collection.name}")
    print(
        "Note: If you need hybrid search features, delete and recreate with the schema above."
    )
except Exception as e:
    if "404" in str(e) or "NotFound" in str(e):
        print(f"Creating collection: {COLLECTION_ID}")
        print(
            "Schema includes: text search fields, auto-embedding config for semantic search"
        )

        request = vectorsearch_v1beta.CreateCollectionRequest(
            parent=parent,
            collection_id=COLLECTION_ID,
            collection=collection_config,
        )
        operation = client.create_collection(request=request)
        collection = operation.result()
        print(f"Collection created: {collection.name}")
    else:
        raise e

Set Up LlamaIndex Components

python

# Imports
from llama_index.core import Settings, StorageContext, VectorStoreIndex
from llama_index.core.schema import TextNode
from llama_index.core.vector_stores.types import (
    MetadataFilters,
    MetadataFilter,
    FilterOperator,
)
from llama_index.embeddings.vertex import VertexTextEmbedding
from llama_index.llms.vertex import Vertex
from llama_index.vector_stores.vertexaivectorsearch import VertexAIVectorStore

# Authentication - get default credentials
import google.auth

credentials, project = google.auth.default()
print(f"Authenticated with project: {project}")

python

# Configure embedding model
embed_model = VertexTextEmbedding(
    model_name="text-embedding-004",
    project=PROJECT_ID,
    location=REGION,
    credentials=credentials,
)

# Configure LLM
llm = Vertex(
    model="gemini-2.0-flash",
    project=PROJECT_ID,
    location=REGION,
    credentials=credentials,
)

# Set as defaults
Settings.embed_model = embed_model
Settings.llm = llm

print("Embedding model and LLM configured successfully!")

Create v2 Vector Store

Creating a v2 vector store is simple - just specify api_version="v2" and your collection_id:

python

# Create v2 vector store
vector_store = VertexAIVectorStore(
    api_version="v2",  # Use v2 API
    project_id=PROJECT_ID,
    region=REGION,
    collection_id=COLLECTION_ID,
    # No index_id, endpoint_id, or gcs_bucket_name needed!
)

print(f"Vector store created with api_version={vector_store.api_version}")

Add Documents

Simple Text Nodes

python

# Create some sample text nodes
texts = [
    "LlamaIndex is a data framework for LLM applications.",
    "Vertex AI Vector Search provides scalable vector similarity search.",
    "RAG combines retrieval with generation for better AI responses.",
    "Embeddings convert text into numerical vectors for similarity matching.",
]

# Create nodes with embeddings
nodes = [
    TextNode(text=text, embedding=embed_model.get_text_embedding(text))
    for text in texts
]

# Add to vector store
ids = vector_store.add(nodes)
print(f"Added {len(ids)} nodes to vector store")

Nodes with Metadata

Add nodes with metadata for filtering and hybrid search:

python

# Sample product data with metadata
products = [
    {
        "text": "Comfortable blue cotton t-shirt, perfect for casual wear",
        "color": "blue",
        "category": "tops",
        "price": 29.99,
    },
    {
        "text": "Professional black dress pants for office meetings",
        "color": "black",
        "category": "bottoms",
        "price": 79.99,
    },
    {
        "text": "Warm green wool sweater for cold winter days",
        "color": "green",
        "category": "tops",
        "price": 59.99,
    },
    {
        "text": "Lightweight blue running shorts with pockets",
        "color": "blue",
        "category": "bottoms",
        "price": 34.99,
    },
    {
        "text": "Elegant red silk blouse for formal occasions",
        "color": "red",
        "category": "tops",
        "price": 89.99,
    },
]

# Create nodes with metadata
# Note: Include "text" in metadata for TEXT_SEARCH to work on the text field
product_nodes = [
    TextNode(
        text=p["text"],
        embedding=embed_model.get_text_embedding(p["text"]),
        metadata={
            "text": p["text"],
            "color": p["color"],
            "category": p["category"],
            "price": p["price"],
        },
    )
    for p in products
]

# Add to vector store
product_ids = vector_store.add(product_nodes)
print(f"Added {len(product_ids)} product nodes with metadata")

Query the Vector Store

Simple Similarity Search

python

# Create index from vector store
storage_context = StorageContext.from_defaults(vector_store=vector_store)
index = VectorStoreIndex.from_vector_store(
    vector_store=vector_store, embed_model=embed_model
)

# Create retriever
retriever = index.as_retriever(similarity_top_k=3)

# Query
results = retriever.retrieve("comfortable clothing for everyday wear")

print("Search Results:")
print("-" * 60)
for result in results:
    print(f"Score: {result.get_score():.3f}")
    print(f"Text: {result.get_text()[:100]}...")
    print(f"Metadata: {result.metadata}")
    print("-" * 60)

Search with Metadata Filters

python

# Filter by color
filters = MetadataFilters(filters=[MetadataFilter(key="color", value="blue")])

retriever = index.as_retriever(filters=filters, similarity_top_k=3)
results = retriever.retrieve("casual clothing")

print("Blue items only:")
print("-" * 60)
for result in results:
    print(
        f"Score: {result.get_score():.3f} | Color: {result.metadata.get('color')}"
    )
    print(f"Text: {result.get_text()[:80]}...")
    print("-" * 60)

python

# Filter by price range
filters = MetadataFilters(
    filters=[
        MetadataFilter(key="price", operator=FilterOperator.LT, value=50.0),
    ]
)

retriever = index.as_retriever(filters=filters, similarity_top_k=3)
results = retriever.retrieve("clothing")

print("Items under $50:")
print("-" * 60)
for result in results:
    print(
        f"Score: {result.get_score():.3f} | Price: ${result.metadata.get('price')}"
    )
    print(f"Text: {result.get_text()[:80]}...")
    print("-" * 60)

RAG Query with LLM

Use the vector store with an LLM for retrieval-augmented generation:

python

# Create query engine
query_engine = index.as_query_engine(similarity_top_k=3)

# Ask a question
response = query_engine.query(
    "What blue clothing items do you have and what are their prices?"
)

print(
    "Question: What blue clothing items do you have and what are their prices?"
)
print("-" * 60)
print(f"Answer: {response.response}")
print("-" * 60)
print("Sources:")
for node in response.source_nodes:
    print(f"  - {node.text[:60]}... (score: {node.score:.3f})")

v2-Only Features

Delete Specific Nodes

python

# Delete specific nodes by ID
# vector_store.delete_nodes(node_ids=["node_id_1", "node_id_2"])
print("delete_nodes() - Delete specific nodes by their IDs")

Clear All Data (v2 only)

v2 supports clearing all data from a collection - this is NOT available in v1:

python

# Clear all data from the collection
# WARNING: This deletes ALL data in the collection!
# vector_store.clear()
print("clear() - Clears all data from collection (v2 only!)")

Hybrid Search (v2 Only)

v2 supports hybrid search, combining vector similarity with text-based search for improved retrieval quality. This is particularly useful when you want to leverage both semantic understanding (vectors) and exact keyword matching (text search).

Supported Query Modes

Mode	Description	Use Case
`DEFAULT`	Dense vector similarity search	Standard semantic search
`TEXT_SEARCH`	Full-text keyword search	Exact keyword matching
`HYBRID`	Vector + Text with RRF fusion	Best of both worlds
`SEMANTIC_HYBRID`	Vector + Semantic search	Auto-embedding semantic search

Ranker Options

Ranker	Description
`rrf` (default)	Reciprocal Rank Fusion with alpha weighting
`vertex`	AI-powered semantic ranking via Vertex AI

Create Hybrid-Enabled Vector Store

To enable hybrid search, set enable_hybrid=True and specify which fields to use for text search:

python

# Create hybrid-enabled vector store
hybrid_vector_store = VertexAIVectorStore(
    api_version="v2",
    project_id=PROJECT_ID,
    region=REGION,
    collection_id=COLLECTION_ID,
    enable_hybrid=True,
    text_search_fields=["text", "category", "color"],  # Fields for text search
    default_hybrid_alpha=0.5,  # Balance between vector and text (0=text only, 1=vector only)
)

print(
    f"Hybrid vector store created with enable_hybrid={hybrid_vector_store.enable_hybrid}"
)

TEXT_SEARCH Mode - Keyword Search

Use TEXT_SEARCH mode for full-text keyword matching. This is useful when you want exact keyword matches rather than semantic similarity:

python

from llama_index.core.vector_stores.types import (
    VectorStoreQuery,
    VectorStoreQueryMode,
)

# TEXT_SEARCH: Full-text keyword search only
text_query = VectorStoreQuery(
    query_str="blue cotton",  # Keywords to search for
    mode=VectorStoreQueryMode.TEXT_SEARCH,
    similarity_top_k=3,
)

results = hybrid_vector_store.query(text_query)

print("TEXT_SEARCH Results (keyword matching):")
print("-" * 60)
for i, node in enumerate(results.nodes):
    print(f"{i+1}. {node.text[:80]}...")
    print(f"   Metadata: {node.metadata}")
    print()

HYBRID Mode - Vector + Text Search

Use HYBRID mode to combine vector similarity with text search. The alpha parameter controls the balance:

alpha=1.0 - Pure vector search
alpha=0.5 - Balanced
alpha=0.0 - Pure text search

python

# Compare different alpha values
print("Comparing alpha values:")
print("=" * 60)

for alpha in [1.0, 0.5, 0.0]:
    query = VectorStoreQuery(
        query_embedding=embed_model.get_query_embedding(
            "warm winter clothing"
        ),
        query_str="sweater green",  # Keywords favor green sweater
        mode=VectorStoreQueryMode.HYBRID,
        alpha=alpha,
        similarity_top_k=2,
    )
    results = hybrid_vector_store.query(query)

    label = (
        "vector only"
        if alpha == 1.0
        else "text only"
        if alpha == 0.0
        else "balanced"
    )
    print(f"\nalpha={alpha} ({label}):")
    for node in results.nodes:
        print(f"  - {node.text[:60]}... | color={node.metadata.get('color')}")

SEMANTIC_HYBRID Mode

SEMANTIC_HYBRID combines your dense vector search with Vertex AI's built-in semantic search. This requires the collection to have vertex_embedding_config configured for auto-embeddings.

python

# SEMANTIC_HYBRID: Vector + Vertex AI's semantic search
# Note: Requires collection with vertex_embedding_config

semantic_query = VectorStoreQuery(
    query_embedding=embed_model.get_query_embedding(
        "professional work attire"
    ),
    query_str="formal office clothing",  # Semantic search text
    mode=VectorStoreQueryMode.SEMANTIC_HYBRID,
    similarity_top_k=3,
)

try:
    results = hybrid_vector_store.query(semantic_query)
    print("SEMANTIC_HYBRID Results:")
    print("-" * 60)
    for i, node in enumerate(results.nodes):
        print(f"{i+1}. {node.text[:80]}...")
except Exception as e:
    print(
        f"SEMANTIC_HYBRID requires collection with vertex_embedding_config: {e}"
    )

Using VertexRanker

Instead of RRF, you can use Vertex AI's semantic ranker for AI-powered result ranking:

python

# Create vector store with VertexRanker
vertex_ranker_store = VertexAIVectorStore(
    api_version="v2",
    project_id=PROJECT_ID,
    region=REGION,
    collection_id=COLLECTION_ID,
    enable_hybrid=True,
    text_search_fields=["text", "category"],
    hybrid_ranker="vertex",  # Use Vertex AI's semantic ranker
    vertex_ranker_model="semantic-ranker-default@latest",
    vertex_ranker_title_field="category",  # Field to use as title
    vertex_ranker_content_field="text",  # Field to use as content
)

# Query with VertexRanker
query = VectorStoreQuery(
    query_embedding=embed_model.get_query_embedding("casual everyday wear"),
    query_str="comfortable shirt",
    mode=VectorStoreQueryMode.HYBRID,
    similarity_top_k=3,
)

results = vertex_ranker_store.query(query)

print("HYBRID with VertexRanker Results:")
print("-" * 60)
for i, node in enumerate(results.nodes):
    print(f"{i+1}. {node.text[:80]}...")
    print(f"   Category: {node.metadata.get('category')}")
    print()

Hybrid Search with Query Engine (RAG)

You can also use hybrid search with the standard LlamaIndex query engine for RAG applications:

python

# Create index with hybrid-enabled vector store
hybrid_storage_context = StorageContext.from_defaults(
    vector_store=hybrid_vector_store
)
hybrid_index = VectorStoreIndex.from_vector_store(
    vector_store=hybrid_vector_store,
    embed_model=embed_model,
)

# Create query engine with hybrid mode
hybrid_query_engine = hybrid_index.as_query_engine(
    vector_store_query_mode=VectorStoreQueryMode.HYBRID,
    similarity_top_k=3,
    alpha=0.7,  # Favor vector search slightly
)

# Ask a question using RAG with hybrid retrieval
response = hybrid_query_engine.query(
    "What comfortable blue clothing options are available?"
)

print("Question: What comfortable blue clothing options are available?")
print("-" * 60)
print(f"Answer: {response.response}")
print("-" * 60)
print("Sources:")
for node in response.source_nodes:
    print(f"  - {node.text[:60]}... (score: {node.score:.3f})")

Hybrid Search Parameters Reference

Parameter	Type	Default	Description
`enable_hybrid`	`bool`	`False`	Enable hybrid search modes
`text_search_fields`	`List[str]`	`None`	Data fields for text search
`embedding_field`	`str`	`"embedding"`	Vector field name
`default_hybrid_alpha`	`float`	`0.5`	Default RRF weight (0=text, 1=vector)
`hybrid_ranker`	`str`	`"rrf"`	Ranker: "rrf" or "vertex"
`semantic_task_type`	`str`	`"RETRIEVAL_QUERY"`	Task type for SemanticSearch
`vertex_ranker_model`	`str`	`"semantic-ranker-default@latest"`	VertexRanker model
`vertex_ranker_title_field`	`str`	`None`	Title field for VertexRanker
`vertex_ranker_content_field`	`str`	`None`	Content field for VertexRanker

Clean Up

Delete the collection when done to avoid charges:

python

CLEANUP = False  # Set to True to delete the collection

if CLEANUP:
    from google.cloud import vectorsearch_v1beta

    client = vectorsearch_v1beta.VectorSearchServiceClient()
    collection_name = (
        f"projects/{PROJECT_ID}/locations/{REGION}/collections/{COLLECTION_ID}"
    )

    print(f"Deleting collection: {collection_name}")
    client.delete_collection(name=collection_name)
    print("Collection deleted.")

Summary

This notebook demonstrated:

Simple Setup: v2 only requires a collection - no index/endpoint deployment
Easy Integration: Just add api_version="v2" to use the new API
Same Interface: All LlamaIndex operations (add, query, delete) work the same
New Features: v2 adds clear() method not available in v1
Hybrid Search: Combine vector and text search for better retrieval:
- TEXT_SEARCH - Full-text keyword search
- HYBRID - Vector + text with RRF fusion
- SEMANTIC_HYBRID - Vector + semantic search
- VertexRanker for AI-powered ranking

Migration from v1

python

# v1 (old)
vector_store = VertexAIVectorStore(
    project_id="...",
    region="...",
    index_id="projects/.../indexes/123",
    endpoint_id="projects/.../indexEndpoints/456",
    gcs_bucket_name="my-bucket"
)

# v2 (new)
vector_store = VertexAIVectorStore(
    api_version="v2",
    project_id="...",
    region="...",
    collection_id="my-collection"
)

# v2 with hybrid search
vector_store = VertexAIVectorStore(
    api_version="v2",
    project_id="...",
    region="...",
    collection_id="my-collection",
    enable_hybrid=True,
    text_search_fields=["text", "title"],
)

For detailed migration instructions, see V2_MIGRATION.md