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Half-Precision Vector: vecf16 ‚Äč

Stored as a half-precision number format, vecf16 takes advantage of the 16-bit float, which uses half the memory and bandwidth compared to vector.

Here's an example of creating a table with a vecf16 column and inserting values:

sql
CREATE TABLE items (
  id bigserial PRIMARY KEY,
  embedding vecf16(3) NOT NULL
);

INSERT INTO items (embedding) VALUES ('[0.1, 0.2, 0]'), ('[0, 0.1, 0.2]');

Index can be created on vecf16 type as well.

sql
CREATE INDEX your_index_name ON items USING vectors (embedding vecf16_l2_ops);

SELECT * FROM items ORDER BY embedding <-> '[0.3,0.2,0.1]' LIMIT 1;

We support three operators to calculate the distance between two vecf16 values.

  • <-> (vecf16_l2_ops): squared Euclidean distance, defined as .
  • <#> (vecf16_dot_ops): negative dot product, defined as .
  • <=> (vecf16_cos_ops): cosine distance, defined as .