Analytical Database

SQL Engine

Dialect

Altertable uses the DuckDB SQL dialect for all queries. If you're familiar with PostgreSQL or SQLite, you'll feel right at home.

Example query:

SELECT
  user_id,
  COUNT(*) AS sessions
FROM altertable.main.web_sessions
WHERE started_at >= date_trunc('week', now())
GROUP BY user_id
ORDER BY sessions DESC
LIMIT 10;

For complete syntax reference, see the DuckDB SQL Documentation.

Data Types

Altertable supports the same data types as DuckDB, including:

Numeric types: INTEGER, BIGINT, DOUBLE, DECIMAL, HUGEINT
Text types: VARCHAR, TEXT
Temporal types: DATE, TIMESTAMP, TIMESTAMPTZ, TIME, INTERVAL
Binary types: BLOB, BITSTRING
Boolean type: BOOLEAN
Nested types: ARRAY, LIST, MAP, STRUCT, UNION
Special types: UUID, JSON

For a complete list of supported data types and their specifications, see the DuckDB Data Types Overview.

Federated Queries

Connect multiple data sources — from BigQuery to Postgres databases — within the same SQL namespace. Query and join across them seamlessly:

SELECT
  u.email,
  b.total_revenue
FROM pg_production.users u
JOIN bigquery.revenue b
  ON u.id = b.user_id;

The engine handles cross-database federation automatically, optimizing query execution across your connected sources.