Changes in version 0.99.2                        

Bug fixes

  - The DuckDB fast-path append now writes new parts into an existing
    hive-partitioned dataset (via the DuckDB APPEND copy option) instead
    of failing with "Directory ... is not empty". A second
    writeCoordArray(..., append = TRUE) slab is preserved alongside the
    first, and the combined dataset round-trips; previously the fast
    path supported only a fresh write.

                       Changes in version 0.99.1                        

Bug fixes

  - The DuckDB fast write path now types the coordinate-index columns
    from the pre-computed, max_dim-aware idxtypes
    (.buildIndexMappings()) instead of inferring them from the remapped
    indices. Previously a > 2^31 along-axis offset made the remapped
    indices a double, which inferred float64 and degraded to a DuckDB
    INTEGER temp column that overflowed; and an append part could narrow
    differently from part 0. The index type now matches the R write path
    and is consistent across parts.

  - writeCoordArray() accepts a whole-number max_dim beyond the 32-bit
    integer range (a coordinate axis larger than ~2.1e9). The validator
    previously coerced max_dim via as.integer(), overflowing such a
    dimension to NA; it now validates integrality without coercion and
    keeps within-32-bit dims as integer.

                       Changes in version 0.9.20                        

New features

  - Fast one-query coercions to concrete sparse-matrix targets: as(x,
    "dgCMatrix") / as(x, "CsparseMatrix") / as(x, "COO_SparseMatrix") /
    as(x, "COO_SparseArray") on a DuckDBArray / DuckDBMatrix now fetch
    the whole COO in a single query and build the target directly,
    skipping the COO_SparseArray -> SVT_SparseArray round-trip the
    default DelayedArray coercions pay for (measured ~1.3-1.7x on a cell
    x gene realize, byte-identical to the default). They fall back to
    the default path when the array is not zero-filled, dropped, the
    wrong rank, or (for dgCMatrix) non-numeric, so correctness is never
    traded for speed. Dense as.matrix / as.array stay on the existing
    (already single-query) path: a direct dense build measured only
    ~1.1x, not worth a separate code path.

Changes

  - The test harness pins DuckDB to a single thread
    (options(DuckDBDataFrame.threads = 1L) in setup.R) so parallel
    floating-point reductions (sum / var_samp) accumulate in a fixed
    order and tight-tolerance expectations stay reproducible run-to-run.
    This is a test-only change; real sessions use all cores.

                       Changes in version 0.9.19                        

Changes

  - Relicensed under the MIT License.

                       Changes in version 0.9.18                        

Bug fixes

  - crossprod() and tcrossprod() on a DuckDBMatrix (the SQL self-join
    form, with no second operand) now raise a clear error before the
    self-join can exhaust memory, instead of silently OOMing on a large
    matrix. The self-join emits roughly nnz^2 / contracted_dim
    intermediate row-pairs before the GROUP BY can reduce them —
    quadratic and un-spillable at scale — so a size estimate now trips a
    stop() with guidance (subset to highly variable genes, or
    materialize with as.matrix()) above a safeguard of 5e8 pairs. The
    threshold is overridable with options(DuckDBArray.gram_pair_limit =
    ) on a machine with more memory.

                       Changes in version 0.9.17                        

Bug fixes

  - The DuckDBTable margin statistics (rowSums/colSums,
    rowMeans/colMeans, rowVars/colVars, rowSds/colSds, rowMaxs/colMaxs,
    rowMins/colMins, rowCounts/colCounts) now honor their na.rm
    argument. Previously na.rm was accepted but ignored — the statistic
    always dropped NA/NULL, diverging from the MatrixGenerics default of
    na.rm = FALSE. Because SQL aggregate functions inherently drop NULL,
    na.rm = FALSE is emulated with a per-group guard: a group containing
    any NULL yields NA. The common na.rm = TRUE path (and any group
    without NULLs) is unchanged.

                       Changes in version 0.9.16                        

Documentation

  - Restructured the vignettes into a user-first set: Introduction to
    DuckDBArray (overview and usage), Benchmarking DuckDBArray (a
    best-effort comparison against in-memory, HDF5Array, and
    TileDBArray), and Implementing the DuckDBArray backend (the
    DelayedArray seed contract and SQL translation, for developers).
  - The benchmarking vignette renders precomputed results (produced
    offline by inst/scripts/run_vignette_benchmarks.R) for both a
    single-threaded and a best-effort-parallel regime, with each backend
    configured at its best and the configuration recorded alongside the
    numbers.
  - Rewrote the README.

Internal changes

  - Added \value sections to all exported-object man pages.
  - Manual-page examples build objects via their constructors/accessors
    instead of accessing S4 slots with @.