b0978812cb
- docs/en/vector.md — add SQL usage section (CREATE TABLE VECTOR, distance functions, <-> operator, CREATE INDEX USING hnsw) - docs/en/baraql.md — update vector search section with real SQL syntax, add VECTOR(n) to data types, update keyword table - docs/en/changelog.md — add Vector SQL Integration and bugfixes to [Unreleased] - docs/ARCHITECTURE.md — add SQL Integration bullet to Vector Engine - README.md — update vector engine section with SQL examples, add Vector SQL to roadmap, bump test count to 340+
3.5 KiB
3.5 KiB
Vector Search Engine
Native HNSW and IVF-PQ indexes for similarity search with full SQL integration.
SQL Usage
Creating Vector Columns
CREATE TABLE items (
id INT PRIMARY KEY,
embedding VECTOR(768)
);
The VECTOR(n) type stores float32 arrays of fixed dimension n.
Inserting Vectors
INSERT INTO items (id, embedding) VALUES (1, '[0.1, 0.2, 0.3, ...]');
Vector Distance Functions
-- Cosine distance (0 = identical, 1 = orthogonal)
SELECT id, cosine_distance(embedding, '[0.1, 0.2, 0.3]') AS dist
FROM items;
-- Euclidean / L2 distance
SELECT id, euclidean_distance(embedding, '[0.1, 0.2, 0.3]') AS dist
FROM items;
-- L2 distance with <-> operator
SELECT id, embedding <-> '[0.1, 0.2, 0.3]' AS dist
FROM items;
-- Inner product (negative dot product for minimization)
SELECT id, inner_product(embedding, '[0.1, 0.2, 0.3]') AS dist
FROM items;
-- Manhattan / L1 distance
SELECT id, l1_distance(embedding, '[0.1, 0.2, 0.3]') AS dist
FROM items;
Nearest Neighbor Search
-- Top-10 nearest neighbors by cosine distance
SELECT id FROM items
ORDER BY cosine_distance(embedding, '[0.1, 0.2, 0.3]') ASC
LIMIT 10;
-- Top-5 nearest neighbors by Euclidean distance
SELECT id FROM items
ORDER BY embedding <-> '[0.1, 0.2, 0.3]'
LIMIT 5;
Vector Indexes
-- Create HNSW index for approximate nearest neighbor search
CREATE INDEX idx_items_vec ON items(embedding) USING hnsw;
-- The index is automatically maintained on INSERT and UPDATE
Supported index methods:
USING hnsw— Hierarchical Navigable Small World (default: cosine metric)USING ivfpq— Inverted File with Product Quantization
Dimension Validation
BaraDB validates vector dimensions at insert time:
-- This will fail: expected 768 dimensions but got 3
INSERT INTO items (id, embedding) VALUES (2, '[1.0, 2.0, 3.0]');
Native Nim API
For embedded or high-performance use, use the native Nim API directly:
import barabadb/vector/engine
var idx = newHNSWIndex(dimensions = 128)
idx.insert(1, @[1.0'f32, 0.0'f32, ...], {"category": "A"}.toTable)
# Search
let results = idx.search(queryVector, k = 10)
# With metadata filtering
let filtered = idx.searchWithFilter(queryVector, k = 10,
filter = proc(meta: Table[string, string]): bool =
return meta.getOrDefault("category") == "A")
Index Types
HNSW
Hierarchical Navigable Small World graph for approximate nearest neighbor search.
var hnsw = newHNSWIndex(
dimensions = 128,
m = 16, # connections per layer
efConstruction = 200, # search width during construction
efSearch = 100 # search width during query
)
IVF-PQ
Inverted File Index with Product Quantization for compression.
var ivfpq = newIVFPQIndex(
dimensions = 128,
numCentroids = 256,
subQuantizers = 8
)
Distance Metrics
| Metric | SQL Function | Description |
|---|---|---|
cosine |
cosine_distance(a, b) |
Cosine dissimilarity (1 - similarity) |
euclidean |
euclidean_distance(a, b) / <-> |
L2 distance |
dotproduct |
inner_product(a, b) |
Negative dot product |
manhattan |
l1_distance(a, b) |
L1 distance |
Quantization
import barabadb/vector/quant
# Scalar quantization
let scalar = scalarQuantize(data, bits = 8)
# Product quantization
let pq = productQuantize(data, subVectors = 8, bits = 8)
SIMD Acceleration
import barabadb/vector/simd
let dist = simdCosineDistance(vec1, vec2)