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This document shows you how to use stored embeddings to generate indexes and query
embeddings. For more information about storing embedding, see
Store vector embeddings.
You can create ScaNN, IVF, IVFFlat, and HNSW indexes with AlloyDB.
Before you begin
Before you can start creating indexes, you must complete the following
prerequisites.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-04-17 UTC."],[[["This guide outlines how to generate and query indexes using stored embeddings within AlloyDB."],["AlloyDB supports the creation of `ScaNN`, `IVF`, `IVFFlat`, and `HNSW` index types."],["Before creating indexes, you must have the `vector` extension (version 0.5.0 or later) installed, with embedding vectors already stored in a table."],["To create `ScaNN` indexes you must also install the `alloydb_scann` extension."],["The `postgres_ann` extension has been renamed to `alloydb_scann`, requiring users to drop old indexes created using `postgres_ann`, upgrade AlloyDB Omni and recreate indexes with `alloydb_scann`."]]],[]]