Randomly Sample Rows from a Spark DataFrame

R/sdf_interface.R

sdf_sample

Description

Draw a random sample of rows (with or without replacement) from a Spark DataFrame.

Usage

sdf_sample(x, fraction = 1, replacement = TRUE, seed = NULL) 

Arguments

Arguments Description
x An object coercable to a Spark DataFrame.
fraction The fraction to sample.
replacement Boolean; sample with replacement?
seed An (optional) integer seed.

Section

Transforming Spark DataFrames

The family of functions prefixed with sdf_ generally access the Scala Spark DataFrame API directly, as opposed to the dplyr interface which uses Spark SQL. These functions will ‘force’ any pending SQL in a dplyr pipeline, such that the resulting tbl_spark object returned will no longer have the attached ‘lazy’ SQL operations. Note that the underlying Spark DataFrame does execute its operations lazily, so that even though the pending set of operations (currently) are not exposed at the R level, these operations will only be executed when you explicitly collect() the table.

See Also

Other Spark data frames: sdf_copy_to(), sdf_distinct(), sdf_random_split(), sdf_register(), sdf_sort(), sdf_weighted_sample()