Embeddings & Vector Search

Embeddings & Vector Search on Google Cloud is the practice of converting text, images, audio, video, logs, documents, or structured records into vector representations and retrieving semantically similar items with managed services such as Vertex AI Vector Search, Vector Search 2.0, BigQuery VECTOR_SEARCH, RAG Engine, Feature Store, AlloyDB, or supported vector stores. It underpins semantic search, hybrid search, RAG grounding, anomaly detection, deduplication, memory retrieval, and multimodal similarity workflows.

Synthesized across 41 notebooks. See the source pages under Notebooks below for line-level grounding.

This area starts with choosing an embedding model and task type that matches the workload, then preparing source data so each embedded item has enough context, clean text or media, stable IDs, and useful metadata. The same embedding model and compatible dimensionality must be used for indexed items and query vectors.

Google Cloud offers several retrieval patterns: Vertex AI Vector Search for managed low-latency nearest-neighbor serving, Vector Search 2.0 collections with schemas and optional auto-embeddings, BigQuery VECTOR_SEARCH for analytics-native workflows, RAG Engine for managed corpus retrieval, and database-backed options such as AlloyDB, Feature Store, Firestore, Weaviate, Chroma, or FAISS depending on scale and production needs.

High-quality systems require more than embedding and indexing: they need chunking, filtering, batching, quota handling, evaluation, threshold tuning, source citations, cleanup of billable resources, and careful handling of sensitive data before embeddings are generated.

Canonical workflow

  1. Enable the required APIs, set project and region explicitly, authenticate, and grant service accounts the IAM roles needed for Vertex AI, BigQuery, Cloud Storage, Document AI, or the selected vector store.
  2. Prepare and clean source data by filtering empty values, normalizing fields, chunking documents, extracting metadata, anonymizing sensitive data when needed, and storing assets such as PDFs, images, or videos in Cloud Storage when required.
  3. Generate embeddings with the appropriate model, task type, dimensionality, batching, retry, throttling, and checkpointing strategy; persist embeddings and metadata for reuse.
  4. Create or configure the vector backend, matching index dimensions, distance measure, update mode, schema, filters, and dense or sparse vector fields to the retrieval use case.
  5. Import, upsert, or sync vectors in batches, then poll long-running operations and verify index readiness, coverage, deployment status, or Feature Store sync completion before querying.
  6. Generate query embeddings with the same compatible model and task type, apply filters consistently, retrieve top-k neighbors, and order results by distance or service-specific ranking.
  7. For RAG or agent workflows, pass retrieved chunks with source metadata into Gemini or the orchestration framework, require answers to stay grounded in retrieved context, and include citations where applicable.
  8. Evaluate retrieval quality with metrics, plots, audits, thresholds, or source inspection, then tune chunking, top-k, distance thresholds, task types, hybrid weights, and cleanup unused billable resources.

Best practices

See Embeddings & Vector Search - Best Practices for the full distilled guide.

  • Use the same embedding model, dimensionality, and compatible distance measure for stored vectors and query vectors.
  • Choose task types deliberately, such as RETRIEVAL_DOCUMENT for indexed content, QUESTION_ANSWERING or RETRIEVAL_QUERY for questions, SEMANTIC_SIMILARITY for similarity baselines, and CLUSTERING for clustering-style anomaly detection.
  • Match index dimensions to embedding output dimensionality; specify output_dimensionality when lower storage cost or faster search is acceptable.
  • Batch embedding, import, upsert, update, delete, and search operations where supported, while respecting per-request limits such as maximum texts, tokens, or datapoints.
  • Throttle embedding and generation traffic, use retries with exponential backoff, checkpoint long-running embedding jobs, and log per-item errors so large jobs can resume.
  • Clean, normalize, and enrich source data before embedding, including removing null or blank text, combining relevant fields, converting HTML to Markdown, normalizing log fields, and preserving metadata such as source URI, page, chunk, and document name.

Key models & APIs

  • gemini-embedding-001, text-embedding-005, text-embedding-004, gemini-embedding-2, gemini-embedding-2-preview, multimodalembedding@001, publishers/google/models/text-embedding-005, publishers/intfloat/models/e5@multilingual-e5-small, google/text-embedding-005, google/siglip2-base-patch16-512, gemini-2.0-flash, gemini-2.5-flash, gemini-3.5-flash, gemini-2.0-flash-live-preview-04-09, Vertex AI Embeddings API, Vertex AI Vector Search, Agent Platform Vector Search, Vector Search 2.0, BigQuery ML ML.GENERATE_EMBEDDING, BigQuery VECTOR_SEARCH, BigQuery VECTOR INDEX, Vertex AI RAG Engine, VertexRagStore, rag.retrieval_query, Vertex AI Feature Store, BigQueryVectorStore, VertexFSVectorStore, AlloyDB vector search, Cloud SQL or AlloyDB pgvector-compatible vector search, Document AI, Cloud DLP, Vertex AI Search, LlamaIndex, LangChain, Chroma, FAISS, Weaviate, Firestore

Notebooks (41)

Agents & ADK (2)

Embeddings & Vector Search (15)

Gemini (23)

Vertex AI Search (1)


Part of the Generative AI Google Brain · Embeddings & Vector Search - Best Practices