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Posted to jira@arrow.apache.org by "José F (Jira)" <ji...@apache.org> on 2022/01/20 20:55:00 UTC
[jira] [Created] (ARROW-15397) Problem with Join in apache arrow in R
José F created ARROW-15397:
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Summary: Problem with Join in apache arrow in R
Key: ARROW-15397
URL: https://issues.apache.org/jira/browse/ARROW-15397
Project: Apache Arrow
Issue Type: Bug
Components: R
Affects Versions: 6.0.1
Reporter: José F
Fix For: 6.0.2
Hi dear arrow developers. I tested inner_join with arrow R package but R crashed, this is my example with toy dataset iris:
data(iris)
write.csv(iris, "iris.csv") # write csv file
# write parket file with write_chunk_data (at the end for interested users)
walk("C:/Users/Stats/Desktop/ejemplo_join/iris.csv",
write_chunk_data, "C:/Users/Stats/Desktop/ejemplo_join/parquet", chunk_size = 50)
iris_arrow <- open_dataset("parquet")
df1_arrow <- iris_arrow %>% select(`...1`, Sepal.Length, Sepal.Width, Petal.Length)
df2_arrow <- iris_arrow %>% select(`...1`, Petal.Width, Species,) d
df <- tabla1_arrow %>% inner_join(tabla2_arrow, by = "...1") %>%
group_by(Species) %>% summarise(prom = mean(Sepal.Length)) %>% collect()
print(df)
# If you want to check function to write parquet file from a csv:
write_chunk_data <- function(data_path, output_dir, chunk_size = 1000000) {
#If the output_dir do not exist, it is created
if (!fs::dir_exists(output_dir)) fs::dir_create(output_dir)
#It gets the name of the file
data_name <- fs::path_ext_remove(fs::path_file(data_path))
#It sets the chunk_num to 0
chunk_num <- 0
#Read the file using vroom
data_chunk <- vroom::vroom(data_path)
#It gets the variable names
data_names <- names(data_chunk)
#It gets the number of rows
rows<-nrow(data_chunk)
#The following loop creates a parquet file for every [chunk_size] rows
repeat{
#It checks if we are over the max rows
if(rows>(chunk_num+1)*chunk_size){
arrow::write_parquet(data_chunk[(chunk_num*chunk_size+1):((chunk_num+1)*chunk_size),],
fs::path(output_dir, glue::glue("\{data_name}-\{chunk_num}.parquet")))
}
else{
arrow::write_parquet(data_chunk[(chunk_num*chunk_size+1):rows,],
fs::path(output_dir, glue::glue("\{data_name}-\{chunk_num}.parquet")))
break
}
chunk_num <- chunk_num + 1
}
#This is to recover some memory and space in the disk
rm(data_chunk)
tmp_file <- tempdir()
files <- list.files(tmp_file, full.names = T, pattern = "^vroom")
file.remove(files)
}
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