9.3.5 Use the ore.groupApply Function

The ore.groupApply function calls an R script with an ore.frame as the input data.

The ore.groupApply function passes the ore.frame to the user-defined input function as the first argument to that function. The INDEX argument to the ore.groupApply function specifies the name of a column of the ore.frame by which Oracle AI Database partitions the rows for processing by the user-defined R function. The ore.groupApply function can use data-parallel runs, in which one or more R engines perform the same R function, or task, on different partitions of data.

The syntax of the ore.groupApply function is the following:

ore.groupApply(X, INDEX, FUN, ..., FUN.VALUE = NULL, FUN.NAME = NULL, FUN.OWNER = NULL,
               parallel = getOption("ore.parallel", NULL))

The ore.groupApply function returns an ore.list object or an ore.frame object.

Examples of the use of the ore.groupApply function are in the following topics:

• Partition on a Single Column
  This example uses the ore.groupApply function and partitions the data on a single column.
• Partition on Multiple Columns
  This example uses the ore.groupApply function and partitions the data on multiple columns.