Carl Boettiger created ARROW-18006: -------------------------------------- Summary: [R] integer coercion on parition variables Key: ARROW-18006 URL: https://issues.apache.org/jira/browse/ARROW-18006 Project: Apache Arrow Issue Type: Bug Components: R Affects Versions: 9.0.0 Reporter: Carl Boettiger
If we partition on a character-string column that is "integer-like", arrow assumes the resulting partition variable is an integer. This is particularly surprising because in most other cases, making a column a partition variable coerces it to a character (makes sense, path names are strings), but in this case we have the opposite coercion where a string becomes an integer. Consider this reprex: {code:java} library(arrow)f <- tempfile() df <- data.frame(x = c("00", "06", "18")) df |> write_dataset(f, partitioning = "x") open_dataset(f) # x is now an integer{code} {code:java} ## fails open_dataset(f) |> filter(x == "00") {code} changing this behavior could break existing code I think, so maybe this shouldn't be considered a bug, but I think it merits discussion. (For instance, we often see large datasets, e.g. from NOAA csv etc, that use zero-padded integers in path names to indicate file-specific metadata. One side effect of the type-coercion is that it also strips the zero-padding) -- This message was sent by Atlassian Jira (v8.20.10#820010)