Quick Start

The steps that follow are designed to get you started with semantic caching quickly and easily. Before using pg_semantic_cache, you must install the following components:

• PostgreSQL version 14, 15, 16, 17, or 18.
• The pgvector extension.
• A C compiler such as gcc or clang.
• PostgreSQL development headers.

Installation

Use the following commands to build the extension from the GitHub repository:

# Clone the repository
git clone https://github.com/pgedge/pg_semantic_cache.git
cd pg_semantic_cache

# Build and install
make clean
make
sudo make install

After building the extension, you need to install and create the extensions you will be using:

-- Install required extensions
CREATE EXTENSION IF NOT EXISTS vector;
CREATE EXTENSION IF NOT EXISTS pg_semantic_cache;

-- Verify installation
SELECT * FROM semantic_cache.cache_health;

Using pg_semantic_cache

Use the following commands to add a result set to a cache, and then query the cache with a similar query:

In the following example, the cache_query function stores a query result with its embedding, and the get_cached_result function retrieves a semantically similar cached result:

SELECT semantic_cache.cache_query(
    query_text := 'What was our Q4 2024 revenue?',
    query_embedding := '[0.123, 0.456, ...]'::text,
    result_data := '{"answer": "Q4 2024 revenue was $2.4M"}'::jsonb,
    ttl_seconds := 1800,
    tags := ARRAY['llm', 'revenue']
);

SELECT * FROM semantic_cache.get_cached_result(
    query_embedding := '[0.124, 0.455, ...]'::text,
    similarity_threshold := 0.95
);