Register an R table function in DuckDB

Registers an R function as a DuckDB table function. The R function is called on the recorded R thread to produce either a finite result (a data frame or named list of equal-length columns) or a rducks_table_stream() producer for scan-time batches. Column types are inferred from the returned columns, and the extension fills DuckDB output vectors directly from the R columns, with no wire serialization for the in-process scan.

Usage

rducks_register_table(con, name, fun, chunk_size = 1024L)

Arguments

con

A duckdb_connection.

name

SQL table function name.

fun

R function returning a data frame, named list of columns, or rducks_table_stream(). Its finite formal argument count defines the SQL positional argument count; each positional argument is registered as DuckDB ANY and converted at bind time from the actual SQL value.

chunk_size

Maximum number of rows emitted per DuckDB output chunk. Must be an integer from 1 to 1024.

Value

Object of class rducks_table_registration containing the connection and normalized table signature. The table function remains registered in DuckDB even if this object is discarded.