# dplyr 1.0.9
* New `rows_append()` which works like `rows_insert()` but ignores keys and
allows you to insert arbitrary rows with a guarantee that the type of `x`
won't change (#6249, thanks to @krlmlr for the implementation and @mgirlich
for the idea).
* The `rows_*()` functions no longer require that the key values in `x` uniquely
identify each row. Additionally, `rows_insert()` and `rows_delete()` no
longer require that the key values in `y` uniquely identify each row. Relaxing
this restriction should make these functions more practically useful for
data frames, and alternative backends can enforce this in other ways as needed
(i.e. through primary keys) (#5553).
* `rows_insert()` gained a new `conflict` argument allowing you greater control
over rows in `y` with keys that conflict with keys in `x`. A conflict arises
if a key in `y` already exists in `x`. By default, a conflict results in an
error, but you can now also `"ignore"` these `y` rows. This is very similar to
the `ON CONFLICT DO NOTHING` command from SQL (#5588, with helpful additions
from @mgirlich and @krlmlr).
* `rows_update()`, `rows_patch()`, and `rows_delete()` gained a new `unmatched`
argument allowing you greater control over rows in `y` with keys that are
unmatched by the keys in `x`. By default, an unmatched key results in an
error, but you can now also `"ignore"` these `y` rows (#5984, #5699).
* `rows_delete()` no longer requires that the columns of `y` be a strict subset
of `x`. Only the columns specified through `by` will be utilized from `y`,
all others will be dropped with a message.
* The `rows_*()` functions now always retain the column types of `x`. This
behavior was documented, but previously wasn't being applied correctly
(#6240).
* The `rows_*()` functions now fail elegantly if `y` is a zero column data frame
and `by` isn't specified (#6179).
# dplyr 1.0.8
* Better display of error messages thanks to rlang 1.0.0.
* `mutate(.keep = "none")` is no longer identical to `transmute()`.
`transmute()` has not been changed, and completely ignores the column ordering
of the existing data, instead relying on the ordering of expressions
supplied through `...`. `mutate(.keep = "none")` has been changed to ensure
that pre-existing columns are never moved, which aligns more closely with the
other `.keep` options (#6086).
* `filter()` forbids matrix results (#5973) and warns about data frame
results, especially data frames created from `across()` with a hint
to use `if_any()` or `if_all()`.
* `slice()` helpers (`slice_head()`, `slice_tail()`, `slice_min()`, `slice_max()`)
now accept negative values for `n` and `prop` (#5961).
* `slice()` now indicates which group produces an error (#5931).
* `cur_data()` and `cur_data_all()` don't simplify list columns in rowwise data frames (#5901).
* dplyr now uses `rlang::check_installed()` to prompt you whether to install
required packages that are missing.
* `storms` data updated to 2020 (@steveharoz, #5899).
* `coalesce()` accepts 1-D arrays (#5557).
* The deprecated `trunc_mat()` is no longer reexported from dplyr (#6141).
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