The arrow package contains methods for 38 dplyr table functions, many of
which are "verbs" that do transformations to one or more tables.
The package also has mappings of 229 R functions to the corresponding
functions in the Arrow compute library. These allow you to write code inside
of dplyr methods that call R functions, including many in packages like
stringr and lubridate, and they will get translated to Arrow and run
on the Arrow query engine (Acero). This document lists all of the mapped
functions.
dplyr verbs
Most verb functions return an arrow_dplyr_query object, similar in spirit
to a dbplyr::tbl_lazy. This means that the verbs do not eagerly evaluate
the query on the data. To run the query, call either compute(),
which returns an arrow Table, or collect(), which pulls the resulting
Table into an R tibble.
anti_join(): thecopyargument is ignoreddistinct():.keep_all = TRUEreturns a non-missing value if present, only returning missing values if all are missing.full_join(): thecopyargument is ignoredinner_join(): thecopyargument is ignoredleft_join(): thecopyargument is ignoredpull(): thenameargument is not supported; returns an R vector by default but this behavior is deprecated and will return an Arrow ChunkedArray in a future release. Provideas_vector = TRUE/FALSEto control this behavior, or setoptions(arrow.pull_as_vector)globally.right_join(): thecopyargument is ignoredsemi_join(): thecopyargument is ignoredslice_head(): slicing within groups not supported; Arrow datasets do not have row order, so head is non-deterministic;proponly supported on queries wherenrow()is knowable without evaluatingslice_max(): slicing within groups not supported;with_ties = TRUE(dplyr default) is not supported;proponly supported on queries wherenrow()is knowable without evaluatingslice_min(): slicing within groups not supported;with_ties = TRUE(dplyr default) is not supported;proponly supported on queries wherenrow()is knowable without evaluatingslice_sample(): slicing within groups not supported;replace = TRUEand theweight_byargument not supported;nonly supported on queries wherenrow()is knowable without evaluatingslice_tail(): slicing within groups not supported; Arrow datasets do not have row order, so tail is non-deterministic;proponly supported on queries wherenrow()is knowable without evaluatingsummarise(): window functions not currently supported; arguments.drop = FALSEand.groups = "rowwise"not supported
Function mappings
In the list below, any differences in behavior or support between Acero and the R function are listed. If no notes follow the function name, then you can assume that the function works in Acero just as it does in R.
Functions can be called either as pkg::fun() or just fun(), i.e. both
str_sub() and stringr::str_sub() work.
In addition to these functions, you can call any of Arrow's 281 compute
functions directly. Arrow has many functions that don't map to an existing R
function. In other cases where there is an R function mapping, you can still
call the Arrow function directly if you don't want the adaptations that the R
mapping has that make Acero behave like R. These functions are listed in the
C++ documentation, and
in the function registry in R, they are named with an arrow_ prefix, such
as arrow_ascii_is_decimal.
base
&<<=>>=as.Date(): MultipletryFormatsnot supported in Arrow. Consider using the lubridate specialised parsing functionsymd(),ymd(), etc.as.difftime(): only supportsunits = "secs"(the default)data.frame():row.namesandcheck.rowsarguments not supported;stringsAsFactorsmust beFALSEdifftime(): only supportsunits = "secs"(the default);tzargument not supportednchar():allowNA = TRUEandkeepNA = TRUEnot supportedpaste(): thecollapseargument is not yet supportedpaste0(): thecollapseargument is not yet supportedstrptime(): accepts aunitargument not present in thebasefunction. Valid values are "s", "ms" (default), "us", "ns".substr():startandstopmust be length 1
dplyr
case_when():.ptypeand.sizearguments not supportedrecode_values():ptypeargument andunmatched = "error"not supported
lubridate
dmy():localeargument not supported; see docs forparse_date_time()mapping for supported formatsdmy_h():localeargument not supported; see docs forparse_date_time()mapping for supported formatsdmy_hm():localeargument not supported; see docs forparse_date_time()mapping for supported formatsdmy_hms():localeargument not supported; see docs forparse_date_time()mapping for supported formatsdpicoseconds(): not supporteddym():localeargument not supported; see docs forparse_date_time()mapping for supported formatsfast_strptime(): non-default values ofltandcutoff_2000not supportedforce_tz(): Timezone conversion from non-UTC timezone not supported;roll_dstvalues of 'error' and 'boundary' are supported for nonexistent times,roll_dstvalues of 'error', 'pre', and 'post' are supported for ambiguous times.make_datetime(): only supports UTC (default) timezonemake_difftime(): only supportsunits = "secs"(the default); providing bothnumand...is not supportedmdy():localeargument not supported; see docs forparse_date_time()mapping for supported formatsmdy_h():localeargument not supported; see docs forparse_date_time()mapping for supported formatsmdy_hm():localeargument not supported; see docs forparse_date_time()mapping for supported formatsmdy_hms():localeargument not supported; see docs forparse_date_time()mapping for supported formatsmy():localeargument not supported; see docs forparse_date_time()mapping for supported formatsmyd():localeargument not supported; see docs forparse_date_time()mapping for supported formatsparse_date_time():quiet = FALSEis not supported Available formats are H, I, j, M, S, U, w, W, y, Y, R, T. On Linux and macOS additionally a, A, b, B, Om, p, r are available.ydm():localeargument not supported; see docs forparse_date_time()mapping for supported formatsydm_h():localeargument not supported; see docs forparse_date_time()mapping for supported formatsydm_hm():localeargument not supported; see docs forparse_date_time()mapping for supported formatsydm_hms():localeargument not supported; see docs forparse_date_time()mapping for supported formatsym():localeargument not supported; see docs forparse_date_time()mapping for supported formatsymd():localeargument not supported; see docs forparse_date_time()mapping for supported formatsymd_h():localeargument not supported; see docs forparse_date_time()mapping for supported formatsymd_hm():localeargument not supported; see docs forparse_date_time()mapping for supported formatsymd_hms():localeargument not supported; see docs forparse_date_time()mapping for supported formatsyq():localeargument not supported; see docs forparse_date_time()mapping for supported formats
stats
median(): approximate median (t-digest) is computedquantile():probsmust be length 1; approximate quantile (t-digest) is computed
stringr
Pattern modifiers coll() and boundary() are not supported in any functions.
str_c(): thecollapseargument is not yet supportedstr_count():patternmust be a length 1 character vectorstr_split(): Case-insensitive string splitting and splitting into 0 parts not supportedstr_sub():startandendmust be length 1