Files
wifi-densepose/crates/ruvector-postgres/examples/sparse_example.sql
ruv d803bfe2b1 Squashed 'vendor/ruvector/' content from commit b64c2172
git-subtree-dir: vendor/ruvector
git-subtree-split: b64c21726f2bb37286d9ee36a7869fef60cc6900
2026-02-28 14:39:40 -05:00

257 lines
8.4 KiB
SQL

-- Sparse Vectors Example Usage
-- This file demonstrates the sparse vector functionality
-- ============================================================================
-- Setup
-- ============================================================================
-- Create extension (assuming already installed)
-- CREATE EXTENSION IF NOT EXISTS ruvector_postgres;
-- Create sample tables
CREATE TABLE IF NOT EXISTS sparse_documents (
id SERIAL PRIMARY KEY,
title TEXT,
content TEXT,
sparse_embedding sparsevec,
created_at TIMESTAMP DEFAULT NOW()
);
-- ============================================================================
-- Inserting Data
-- ============================================================================
-- Method 1: String format
INSERT INTO sparse_documents (title, content, sparse_embedding) VALUES
('Machine Learning Basics',
'Introduction to neural networks and deep learning',
'{1024:0.5, 2048:0.3, 4096:0.8, 8192:0.2}'::sparsevec),
('Natural Language Processing',
'Text processing and language models',
'{1024:0.3, 3072:0.7, 4096:0.4, 9216:0.6}'::sparsevec),
('Computer Vision',
'Image recognition and object detection',
'{2048:0.9, 5120:0.4, 6144:0.5, 7168:0.3}'::sparsevec);
-- Method 2: Array construction
INSERT INTO sparse_documents (title, content, sparse_embedding) VALUES
('Reinforcement Learning',
'Q-learning and policy gradients',
ruvector_to_sparse(
ARRAY[1024, 4096, 10240]::int[],
ARRAY[0.6, 0.8, 0.4]::real[],
30000
));
-- Method 3: Convert from dense
INSERT INTO sparse_documents (title, sparse_embedding)
SELECT 'From Dense Vector',
ruvector_dense_to_sparse(
ARRAY[0, 0.5, 0, 0.3, 0, 0, 0.8, 0, 0, 0.2]::real[]
);
-- ============================================================================
-- Basic Queries
-- ============================================================================
-- View all documents with sparse vectors
SELECT id, title,
ruvector_sparse_nnz(sparse_embedding) as num_nonzero,
ruvector_sparse_dim(sparse_embedding) as dimension,
ruvector_sparse_norm(sparse_embedding) as l2_norm
FROM sparse_documents;
-- ============================================================================
-- Similarity Search
-- ============================================================================
-- Define a query vector
WITH query AS (
SELECT '{1024:0.5, 2048:0.3, 4096:0.8}'::sparsevec AS query_vec
)
-- Search by dot product (inner product)
SELECT d.id, d.title,
ruvector_sparse_dot(d.sparse_embedding, q.query_vec) AS dot_product,
ruvector_sparse_cosine(d.sparse_embedding, q.query_vec) AS cosine_sim,
ruvector_sparse_euclidean(d.sparse_embedding, q.query_vec) AS euclidean_dist
FROM sparse_documents d, query q
ORDER BY dot_product DESC
LIMIT 5;
-- Find documents with high cosine similarity
WITH query AS (
SELECT '{1024:0.5, 4096:0.8}'::sparsevec AS query_vec
)
SELECT id, title,
ruvector_sparse_cosine(sparse_embedding, query_vec) AS similarity
FROM sparse_documents, query
WHERE ruvector_sparse_cosine(sparse_embedding, query_vec) > 0.3
ORDER BY similarity DESC;
-- ============================================================================
-- Sparsification Operations
-- ============================================================================
-- Keep only top-k elements
SELECT id, title,
sparse_embedding AS original,
ruvector_sparse_top_k(sparse_embedding, 2) AS top_2_elements
FROM sparse_documents
LIMIT 3;
-- Prune small values
SELECT id, title,
sparse_embedding AS original,
ruvector_sparse_prune(sparse_embedding, 0.4) AS pruned
FROM sparse_documents
LIMIT 3;
-- ============================================================================
-- BM25 Text Search Example
-- ============================================================================
-- Create BM25-specific table
CREATE TABLE IF NOT EXISTS bm25_articles (
id SERIAL PRIMARY KEY,
title TEXT,
content TEXT,
term_frequencies sparsevec, -- TF values
doc_length REAL
);
-- Insert sample documents with term frequencies
INSERT INTO bm25_articles (title, content, term_frequencies, doc_length) VALUES
('AI Research Paper',
'Deep learning models for natural language processing',
'{100:2.0, 200:1.0, 300:3.0, 400:1.0}'::sparsevec, -- TF values
7.0),
('Machine Learning Tutorial',
'Introduction to supervised and unsupervised learning',
'{100:1.0, 250:2.0, 300:1.0, 500:2.0}'::sparsevec,
6.0),
('Data Science Guide',
'Statistical analysis and data visualization techniques',
'{150:1.0, 250:1.0, 350:2.0, 450:1.0}'::sparsevec,
6.0);
-- BM25 search
WITH
query AS (
-- Query with IDF weights (normally computed from corpus)
SELECT '{100:1.5, 300:2.0, 400:1.2}'::sparsevec AS query_idf
),
collection_stats AS (
SELECT AVG(doc_length) AS avg_doc_len
FROM bm25_articles
)
SELECT a.id, a.title,
ruvector_sparse_bm25(
q.query_idf,
a.term_frequencies,
a.doc_length,
cs.avg_doc_len,
1.2, -- k1 parameter
0.75 -- b parameter
) AS bm25_score
FROM bm25_articles a, query q, collection_stats cs
ORDER BY bm25_score DESC
LIMIT 5;
-- ============================================================================
-- Hybrid Search (Dense + Sparse)
-- ============================================================================
-- Create hybrid table (requires vector extension)
-- Uncomment if you have dense vector support
/*
CREATE TABLE IF NOT EXISTS hybrid_documents (
id SERIAL PRIMARY KEY,
title TEXT,
dense_embedding vector(768),
sparse_embedding sparsevec
);
-- Hybrid search combining both signals
WITH query AS (
SELECT
random_vector(768) AS query_dense, -- Replace with actual query
'{1024:0.5, 2048:0.3}'::sparsevec AS query_sparse
)
SELECT id, title,
0.7 * (1 - (dense_embedding <=> query_dense)) + -- Dense similarity
0.3 * ruvector_sparse_dot(sparse_embedding, query_sparse) AS hybrid_score
FROM hybrid_documents, query
ORDER BY hybrid_score DESC
LIMIT 10;
*/
-- ============================================================================
-- Utility Operations
-- ============================================================================
-- Convert sparse to dense
SELECT id, title,
ruvector_sparse_to_dense(sparse_embedding) AS dense_array
FROM sparse_documents
LIMIT 3;
-- Get vector statistics
SELECT
COUNT(*) as num_documents,
AVG(ruvector_sparse_nnz(sparse_embedding)) AS avg_nonzero,
MIN(ruvector_sparse_nnz(sparse_embedding)) AS min_nonzero,
MAX(ruvector_sparse_nnz(sparse_embedding)) AS max_nonzero,
AVG(ruvector_sparse_norm(sparse_embedding)) AS avg_norm
FROM sparse_documents;
-- Find documents with similar sparsity
WITH target AS (
SELECT sparse_embedding, ruvector_sparse_nnz(sparse_embedding) AS target_nnz
FROM sparse_documents
WHERE id = 1
)
SELECT d.id, d.title,
ruvector_sparse_nnz(d.sparse_embedding) AS doc_nnz,
ABS(ruvector_sparse_nnz(d.sparse_embedding) - t.target_nnz) AS nnz_diff
FROM sparse_documents d, target t
WHERE d.id != 1
ORDER BY nnz_diff
LIMIT 5;
-- ============================================================================
-- Performance Analysis
-- ============================================================================
-- Check storage size
SELECT id, title,
pg_column_size(sparse_embedding) AS sparse_bytes,
ruvector_sparse_nnz(sparse_embedding) AS num_nonzero,
pg_column_size(sparse_embedding)::float /
GREATEST(ruvector_sparse_nnz(sparse_embedding), 1) AS bytes_per_element
FROM sparse_documents
ORDER BY sparse_bytes DESC;
-- Batch similarity computation
EXPLAIN ANALYZE
WITH queries AS (
SELECT generate_series(1, 3) AS query_id,
'{1024:0.5, 2048:0.3}'::sparsevec AS query_vec
)
SELECT q.query_id, d.id, d.title,
ruvector_sparse_dot(d.sparse_embedding, q.query_vec) AS score
FROM sparse_documents d
CROSS JOIN queries q
ORDER BY q.query_id, score DESC;
-- ============================================================================
-- Cleanup (optional)
-- ============================================================================
-- DROP TABLE IF EXISTS sparse_documents CASCADE;
-- DROP TABLE IF EXISTS bm25_articles CASCADE;
-- DROP TABLE IF EXISTS hybrid_documents CASCADE;