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. The schema is either Built-In or stored remotely in the Repository.

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.

This component offers the
advantage of the dynamic schema feature. This allows you to retrieve unknown columns
from source files or to copy batches of columns from a source without mapping each
column individually. For further information about dynamic schemas, see
Talend Studio

User Guide.

This dynamic schema
feature is designed for the purpose of retrieving unknown columns of a table and is
recommended to be used for this purpose only; it is not recommended for the use of
creating tables.

Built-In: You create and store the
schema locally for this component only. Related topic: see
Talend Studio

User Guide.

Repository: You have already created
the schema and stored it in the Repository. You can reuse it in various projects and
Job designs. Related topic: see
Talend Studio

User Guide.

Displays each row of the output flow as a key-value list.

With this mode selected, you can choose to show either the unique
name or the label of component, or both of them, for each output
row.

Separator

(For Basic mode only)

Enter the separator which will delimit data on the Log
display.

Print header

(For Basic mode only)

Print component unique name in front of each
output row

(For Basic mode only)

Select this check box to show the unique name the component in
front of each output row to differentiate outputs in case several
tLogRow components are
used.

Print schema column name in front of each
value

(For Basic mode only)

Select this check box to retrieve column labels from output
schema.

Use fixed length for values

(For Basic mode only)

Select this check box to set a fixed width for the value
display.

Global Variables

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space to access the variable list and choose the variable to use from it.

For further information about variables, see
Talend Studio

User Guide.

Usage rule

This component can be used as intermediate step in a data flow or
as a n end object in the Job flowchart.

In a
Talend
Map/Reduce Job, this component is used as an intermediate or
an end step. It generates native Map/Reduce code that can be executed directly in
Hadoop.

You need to use the Hadoop Configuration tab in the
Run view to define the connection to a given Hadoop
distribution for the whole Job.

This connection is effective on a per-Job basis.

For further information about a
Talend
Map/Reduce Job, see the sections
describing how to create, convert and configure a
Talend
Map/Reduce Job of the

Talend Open Studio for Big Data Getting Started
Guide
.

Note that in this documentation, unless otherwise
explicitly stated, a scenario presents only Standard Jobs,
that is to say traditional
Talend
data integration Jobs, and non Map/Reduce Jobs.