[ARROW-7028] [R] Date roundtrip results in different R storage mode

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.15.0
• Fix Version/s: 1.0.0
• Component/s: R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/23339
• Assignee: Romain Francois
• Reporter: Sascha
• Created: 30/Oct/19 09:35
• Updated: 11/Jan/23 07:51
• Resolved: 17/Jun/20 17:07

Description

When saving R-dataframes with parquet and loading them again, the internal representation of Dates changes, leading e.g. to errors when comparing them in dplyr::if_else.

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#> filter, lag
#> The following objects are masked from 'package:base':
#> 
#> intersect, setdiff, setequal, union

tmp = tempdir()
dat = tibble(tag = as.Date("2018-01-01"))
dat2 = tibble(tag2 = as.Date("2019-01-01"))

arrow::write_parquet(dat, file.path(tmp, "dat.parquet"))
dat = arrow::read_parquet(file.path(tmp, "dat.parquet"))

typeof(dat$tag)
#> [1] "integer"
typeof(dat2$tag2)
#> [1] "double"

bind_cols(dat, dat2) %>%
 mutate(comparison = if_else(TRUE, tag, tag2))
#> `false` must be a `Date` object, not a `Date` object

Created on 2019-10-30 by the [reprex package](https://reprex.tidyverse.org) (v0.3.0)

Issue Links

• links to: GitHub Pull Request #7415