git clone --branch v0.8.0 https://github.com/pgvector/pgvector.git
cd pgvector
make
sudo make install

CREATE EXTENSION vector;

CREATE TABLE items (
  id bigserial PRIMARY KEY,
  embedding vector(3)
);

INSERT INTO items (embedding) VALUES ('[1,2,3]'), ('[4,5,6]');

SELECT * FROM items
ORDER BY embedding <-> '[3,1,2]'
LIMIT 5;

SELECT AVG(embedding) FROM items;

CREATE INDEX ON items USING hnsw (embedding vector_l2_ops);

SET hnsw.ef_search = 40;

CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 100);
SET ivfflat.probes = 10;

SELECT extversion FROM pg_extension WHERE extname='vector';
ALTER EXTENSION vector UPDATE;

CREATE TABLE employees (
    employee_id INT,
    department VARCHAR(50),
    start_date DATE,
    end_date DATE
); 

WITH ordered_periods AS (
  SELECT *,
         LAG(end_date) OVER (PARTITION BY employee_id, department ORDER BY start_date) AS prev_end
  FROM employees
),
grouped_periods AS (
  SELECT *,
         CASE
           WHEN prev_end IS NULL OR prev_end + INTERVAL '1 day' < start_date THEN 1
           ELSE 0
         END AS is_new_group
  FROM ordered_periods
),
group_tags AS (
  SELECT *,
         SUM(is_new_group) OVER (PARTITION BY employee_id, department ORDER BY start_date) AS group_id
  FROM grouped_periods
),
grouped_ranges AS (
  SELECT employee_id, department, group_id,
         MIN(start_date) AS period_start,
         MAX(COALESCE(end_date, CURRENT_DATE)) AS period_end
  FROM group_tags
  GROUP BY employee_id, department, group_id
),
long_periods AS (
  SELECT employee_id, department, period_start, period_end,
         (period_end - period_start) AS duration_days
  FROM grouped_ranges
  WHERE period_end - period_start > INTERVAL '3 years'
)
SELECT *
FROM long_periods;

curl -LsSf https://raw.githubusercontent.com/theseus-rs/rsql/main/install.sh | sh

# Одноразовый запрос к SQLite
rsql --url "sqlite://file.db" -- "SELECT * FROM users LIMIT 5;"

# Интерактивная сессия с PostgreSQL
rsql --url "postgres://user:pass@localhost/db"