Comparing read_csv with spark_read_csv

Reading in a csv file into R using dplyr’s `read_csv()` function is so simple. The syntax & parameters of dplyr are fairly easy to remember, once you’ve done it a few times.

read_csv(file, 
    col_names = TRUE, 
    col_types = NULL,
    locale = default_locale(),
    na = c(“”, “NA”), 
    quoted_na = TRUE,
    quote = “””, 
    comment = “”, 
    trim_ws = TRUE, 
    skip = 0, n_max = Inf,
    guess_max = min(1000, n_max), 
    progress = show_progress()
)

I’ve only just started working with big data sets, & was began wondering if what I know about the dplyr syntax can be carried over to sparklyr’s spark_read_csv() function.

While not exactly the same, but if you know one, you can quite easily pick the other. There’s an additional parameter `sc`, aka spark connection, that’s required.

spark_read_csv(
    sc, 
    name,
    path, 
    header = TRUE, # FALSE forces a “V_” prefix
    columns = NULL,
    infer_schema = TRUE, # to infer column data type
    delimiter = “,”, 
    quote = “””, 
    escape = “\”,
    charset = “UTF-8”, 
    null_value = NULL,
    options = list(),
    repartition = 0, # number of partitions to distribute the generated table.
    memory = TRUE, 
    overwrite = TRUE, …
)

Leave a Reply

Your email address will not be published. Required fields are marked *

Your post must include a link to this post.

How does this work?
Write a response on your own website and include a link to this post. Then submit your response’s URL here. Your response may appear here after moderation. To update or remove it, edit or delete your original post and submit the same URL again. Learn more about Webmentions.