acero function

Functions available in Arrow dplyr queries

The arrow package contains methods for 37 dplyr table functions, many of which are "verbs" that do transformations to one or more tables. The package also has mappings of 213 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(): the copy argument is ignored
• arrange()
• collapse()
• collect()
• compute()
• count()
• distinct(): .keep_all = TRUE returns a non-missing value if present, only returning missing values if all are missing.
• explain()
• filter()
• full_join(): the copy argument is ignored
• glimpse()
• group_by()
• group_by_drop_default()
• group_vars()
• groups()
• inner_join(): the copy argument is ignored
• left_join(): the copy argument is ignored
• mutate()
• pull(): the name argument is not supported; returns an R vector by default but this behavior is deprecated and will return an Arrow ChunkedArray in a future release. Provide as_vector = TRUE/FALSE to control this behavior, or set options(arrow.pull_as_vector) globally.
• relocate()
• rename()
• rename_with()
• right_join(): the copy argument is ignored
• select()
• semi_join(): the copy argument is ignored
• show_query()
• slice_head(): slicing within groups not supported; Arrow datasets do not have row order, so head is non-deterministic; prop only supported on queries where nrow() is knowable without evaluating
• slice_max(): slicing within groups not supported; with_ties = TRUE (dplyr default) is not supported; prop only supported on queries where nrow() is knowable without evaluating
• slice_min(): slicing within groups not supported; with_ties = TRUE (dplyr default) is not supported; prop only supported on queries where nrow() is knowable without evaluating
• slice_sample(): slicing within groups not supported; replace = TRUE and the weight_by argument not supported; n only supported on queries where nrow() is knowable without evaluating
• slice_tail(): slicing within groups not supported; Arrow datasets do not have row order, so tail is non-deterministic; prop only supported on queries where nrow() is knowable without evaluating
• summarise(): window functions not currently supported; arguments .drop = FALSE and .groups = "rowwise" not supported
• tally()
• transmute()
• ungroup()
• union()
• union_all()

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 271 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.

arrow

• add_filename()
• cast()
• one()

base

• !
• !=
• %%
• %/%
• %in%
• &
• *
• +
• -
• /
• \<
• \<=
• ==
• \>
• \>=
• ISOdate()
• ISOdatetime()
• ^
• abs()
• acos()
• all()
• any()
• as.Date(): Multiple tryFormats not supported in Arrow. Consider using the lubridate specialised parsing functions ymd(), ymd(), etc.
• as.character()
• as.difftime(): only supports units = "secs" (the default)
• as.double()
• as.integer()
• as.logical()
• as.numeric()
• asin()
• ceiling()
• cos()
• data.frame(): row.names and check.rows arguments not supported; stringsAsFactors must be FALSE
• difftime(): only supports units = "secs" (the default); tz argument not supported
• endsWith()
• exp()
• floor()
• format()
• grepl()
• gsub()
• ifelse()
• is.character()
• is.double()
• is.factor()
• is.finite()
• is.infinite()
• is.integer()
• is.list()
• is.logical()
• is.na()
• is.nan()
• is.numeric()
• log()
• log10()
• log1p()
• log2()
• logb()
• max()
• mean()
• min()
• nchar(): allowNA = TRUE and keepNA = TRUE not supported
• paste(): the collapse argument is not yet supported
• paste0(): the collapse argument is not yet supported
• pmax()
• pmin()
• prod()
• round()
• sign()
• sin()
• sqrt()
• startsWith()
• strftime()
• strptime(): accepts a unit argument not present in the base function. Valid values are "s", "ms" (default), "us", "ns".
• strrep()
• strsplit()
• sub()
• substr(): start and stop must be length 1
• substring()
• sum()
• tan()
• tolower()
• toupper()
• trunc()
• |

bit64

• as.integer64()
• is.integer64()

dplyr

• across()
• between()
• case_when(): .ptype and .size arguments not supported
• coalesce()
• desc()
• if_all()
• if_any()
• if_else()
• n()
• n_distinct()

lubridate

• am()
• as_date()
• as_datetime()
• ceiling_date()
• date()
• date_decimal()
• day()
• ddays()
• decimal_date()
• dhours()
• dmicroseconds()
• dmilliseconds()
• dminutes()
• dmonths()
• dmy(): locale argument not supported
• dmy_h(): locale argument not supported
• dmy_hm(): locale argument not supported
• dmy_hms(): locale argument not supported
• dnanoseconds()
• dpicoseconds(): not supported
• dseconds()
• dst()
• dweeks()
• dyears()
• dym(): locale argument not supported
• epiweek()
• epiyear()
• fast_strptime(): non-default values of lt and cutoff_2000 not supported
• floor_date()
• force_tz(): Timezone conversion from non-UTC timezone not supported; roll_dst values of 'error' and 'boundary' are supported for nonexistent times, roll_dst values of 'error', 'pre', and 'post' are supported for ambiguous times.
• format_ISO8601()
• hour()
• is.Date()
• is.POSIXct()
• is.instant()
• is.timepoint()
• isoweek()
• isoyear()
• leap_year()
• make_date()
• make_datetime(): only supports UTC (default) timezone
• make_difftime(): only supports units = "secs" (the default); providing both num and ... is not supported
• mday()
• mdy(): locale argument not supported
• mdy_h(): locale argument not supported
• mdy_hm(): locale argument not supported
• mdy_hms(): locale argument not supported
• minute()
• month()
• my(): locale argument not supported
• myd(): locale argument not supported
• parse_date_time(): quiet = FALSE is not supported Available formats are H, I, j, M, S, U, w, W, y, Y, R, T. On Linux and OS X additionally a, A, b, B, Om, p, r are available.
• pm()
• qday()
• quarter()
• round_date()
• second()
• semester()
• tz()
• wday()
• week()
• with_tz()
• yday()
• ydm(): locale argument not supported
• ydm_h(): locale argument not supported
• ydm_hm(): locale argument not supported
• ydm_hms(): locale argument not supported
• year()
• ym(): locale argument not supported
• ymd(): locale argument not supported
• ymd_h(): locale argument not supported
• ymd_hm(): locale argument not supported
• ymd_hms(): locale argument not supported
• yq(): locale argument not supported

methods

• is()

rlang

• is_character()
• is_double()
• is_integer()
• is_list()
• is_logical()

stats

• median(): approximate median (t-digest) is computed
• quantile(): probs must be length 1; approximate quantile (t-digest) is computed
• sd()
• var()

stringi

• stri_reverse()

stringr

Pattern modifiers coll() and boundary() are not supported in any functions.

• str_c(): the collapse argument is not yet supported
• str_count(): pattern must be a length 1 character vector
• str_detect()
• str_dup()
• str_ends()
• str_length()
• str_like()
• str_pad()
• str_remove()
• str_remove_all()
• str_replace()
• str_replace_all()
• str_split(): Case-insensitive string splitting and splitting into 0 parts not supported
• str_starts()
• str_sub(): start and end must be length 1
• str_to_lower()
• str_to_title()
• str_to_upper()
• str_trim()

tibble

• tibble()

tidyselect

• all_of()
• contains()
• ends_with()
• everything()
• last_col()
• matches()
• num_range()
• one_of()
• starts_with()