A DuckDB-backed S4Vectors DataFrame — out-of-core tabular data, stored as Parquet.

DuckDBDataFrame provides a S4Vectors DataFrame backed by DuckDB over columnar Parquet. It behaves like an ordinary DataFrame --- $, [, mcols(), cbind() --- but the data stays on disk and operations are recorded as lazy SQL queries, so you can subset, add computed columns, and aggregate without loading the table into memory.

It is the tabular foundation of the BiocDuckDB suite: DuckDBArray (a DuckDB-backed DelayedArray) and DuckDBGRanges (a DuckDB-backed GRanges) both build on the underlying DuckDBTable abstraction.

The package ships five classes: DuckDBTable (the n-dimensional SQL-backed table), DuckDBDataFrame (its 2-D DataFrame case), DuckDBColumn (a single atomic column), DuckDBAtomicList (DuckDB LIST[] columns), and DuckDBEmbeddings (fixed-length ARRAY[n] columns).

# once available from Bioconductor:
if (!require("BiocManager")) install.packages("BiocManager")
BiocManager::install("DuckDBDataFrame")

library(DuckDBDataFrame)
library(arrow)

mtcars_df <- cbind(model = rownames(mtcars), mtcars)
path <- tempfile(fileext = ".parquet")
write_parquet(mtcars_df, path)

df <- DuckDBDataFrame(path, datacols = colnames(mtcars),
                      keycol = list(model = mtcars_df$model))

df[df$mpg > 25, c("mpg", "cyl")]    # lazy, on-disk subset
df$efficiency <- df$mpg / df$hp      # lazy computed column

$ returns a column (a DuckDBColumn, still lazy) that materializes with as.vector(); mcols() and the rest of the DataFrame API work as usual. DuckDB's SQL functions are reachable via sql_fun() / sql_call(), and the shared connection via dbconn().

A good fit when the table is larger than memory (or you want to keep memory free), when the workload is columnar (filtering, aggregation, selecting a few columns of a wide table), or when the data already lives on disk as Parquet that other tools should read. An in-memory DataFrame remains preferable for small tables and for row-wise or heavy random-access work.

• Introduction to DuckDBDataFrame — motivation, construction, and the common operations (vignettes/DuckDBDataFrame.Rmd).
• Design and extension of DuckDBDataFrame — the DuckDBTable abstraction, SQL translation, connection model, and how other packages extend it, for developers (vignettes/DuckDBDataFrame-design.Rmd).

MIT License. Copyright Genentech, Inc., 2026.