Is the ducklake DuckDB extension usable?

Reports whether the ducklake DuckDB extension is already installed and can be loaded. The check opens a throwaway in-memory DuckDB connection, asks DuckDB's extension catalog whether the extension is installed, and loads it only if so. Reading the catalog cannot download anything, and loading an installed extension does not reach the network, so the probe never downloads and never writes to the extension directory. The connection is opened on the directory duckdb would resolve for a new connection, so an existing ~/.duckdb is found, and the offer duckdb makes to create one is not triggered. The package's own connection is left untouched.

Usage

ducklake_extension_available()

Value

A single logical: TRUE when the extension loads, FALSE otherwise (including when a connection cannot be opened).

Details

Use it to guard code that should degrade gracefully when the extension is absent: examples, vignettes, tests, and conditional branches in scripts. The package's own examples are gated on it. There is no need to call it before attach_ducklake(), which installs the extension the first time it is needed; install_ducklake() downloads it ahead of time.

A FALSE on a machine where the extension was installed earlier usually means it went into a temporary directory. duckdb keeps extensions under a "home" directory: the duckdb.home option or DUCKDB_R_HOME when set, otherwise ~/.duckdb when it exists (in an interactive session duckdb offers to create it the first time it connects), otherwise a per-session temporary directory. See ?duckdb::duckdb_storage.

The result is cached for the rest of the session, since spinning up DuckDB to re-answer the same question is wasteful when dozens of examples ask it. install_ducklake() and a first-use install by attach_ducklake() clear the cache, so a FALSE answer becomes TRUE as soon as the extension is there.

See also

Other connection management: attach_ducklake(), create_storage_secret(), detach_ducklake(), get_ducklake_backend(), get_ducklake_connection(), get_ducklake_info(), install_ducklake(), set_ducklake_connection()

Examples

if (ducklake_extension_available()) {
  message("ducklake extension is ready to use")
} else {
  message("attach_ducklake() will download it on first use")
}
#> ducklake extension is ready to use