tDataShuffling Standard properties - 7.0

Schema and Edit Schema

A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields.

Click Sync columns to retrieve the schema from the previous component connected in the Job.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

• View schema: choose this option to view the schema only.

• Change to built-in property: choose this option to change the schema to Built-in for local changes.

• Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

Built-In: You create and store the schema locally for this component only.

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs.

Shuffling columns

Define the groups of columns to be shuffled:

• Column: Select the columns to be shuffled.

• Group ID: Select the group identifier to group columns. The columns having the same group identifier are shuffled together.

  This field is set to 0 by default. This means that the column is not part of the shuffling process.

Seed for random generator

Set a random number if you want to shuffle the data in the same order in each execution of the Job. This field is set to 12345678 by default.

Repeating the execution with a different value for this field will shuffle the data in a different order. Keep this field empty if you want the data to be shuffled in random order each time you execute the Job.

Buffer size

Type in the size of physical memory, in number of rows, you want to allocate to processed data.

Partitioning columns

Add the columns used for partitioning the data.

The selected columns separate the shuffling process into small partitions. Only the rows within a partition can be shuffled together.

tStat Catcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

Usage rule

This component is usually used as an intermediate component, and it requires an input component and an output component.