tHashOutput – Docs for ESB 5.x

Component family

Technical

Function

tHashOutput writes data to the
cache memory for high-speed access.

Purpose

This component loads data to the cache memory to offer high-speed
access, facilitating transactions involving a large amount of
data.

Basic settings

Schema and Edit
schema

A schema is a row description, it defines the number of fields to
be processed and passed on to the next component. The schema is
either built-in or remotely stored 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:

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

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: The schema is created
and stored locally for this component only. Related topic: see the
Talend Studio User
Guide.

Repository: The schema already
exists and is stored in the Repository, hence can be reused. Related
topic: see the Talend Studio User
Guide.

Link with a tHashOutput

Select this check box to connect to a tHashOutput component.

Component list

Drop-down list of available tHashOutput components.

Data write model

Drop-down list of available data write modes.

Keys management

Drop-down list of available keys management modes.

Append

Selected by default, this option is designed to append data to the
memory in case an iterator exists in the same subjob. If it is
unchecked, tHashOutput will clear
the memory before loading data to it.

Advanced settings

tStatCatcher Statistics

Select this check box to collect log data at the component
level.

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.

NB_LINE: the number of rows processed. This is an After
variable and it returns an integer.

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

This component writes data to the cache memory and is closely
related to tHashInput. Together,
these twin components offer high-speed data access to facilitate
transactions involving a massive amount of data.

Limitation

n/a