Virtual Servers

Perspective's Virtual Server feature lets you connect <perspective-viewer> to external data sources without loading data into Perspective's built-in engine. Instead, queries are translated and executed natively by the external database.

For a detailed explanation of how virtual servers work, see the Virtual Servers concepts page.

Perspective ships with built-in virtual server implementations for:

• DuckDB — query DuckDB databases using the duckdb Python package.
• ClickHouse — query a ClickHouse server using the clickhouse-connect Python package.
• Polars — query in-memory Polars DataFrames using the polars Python package.
• PostgreSQL — query a PostgreSQL server (16 or later) using the psycopg Python package.

You can also implement your own virtual server to connect Perspective to any data source by subclassing VirtualServerHandler.