# tSurviveFields Centralizes data from various and heterogeneous sources to create a master copy of data. tSurviveFields receives a flow and merges it based on one or more columns. The aggregation key and the relevant result of operations (such as min, max, sum etc) are provided for each output line. This component is not shipped with your Talend Studio by default. You need to install it using the Feature Manager. For more information, see [Installing features using the Feature Manager](https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/install-features-to-talend-studio). ## tSurviveFields Standard properties These properties are used to configure tSurviveFields running in the Standard Job framework. The Standard tSurviveFields component belongs to the Data Quality and the Processing families. This component is available in Talend Data Management Platform, Talend Big Data Platform, Talend Real-Time Big Data Platform, Talend Data Services Platform and in Talend Data Fabric. ## Basic settings | Properties | Description | | --- | --- | | 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 stored remotely in the Repository.
Built-in: The schema will be created and stored locally for this component only. For more information about a component schema in its Basic settings tab, see Basic settings tab.
Repository: The schema already exists and is stored in the Repository, hence can be reused in various projects and Job designs. For more information about a component schema in its Basic settings tab, see Basic settings tab.

| | Key | Define the merge sets, the values of which will be used for calculations.

Output column: Select the column name from the list
that reflects the schema structure you defined. You can add as many output columns
as you wish to make more precise aggregations.

Input column: Match each input column name with
your output columns, in case the output column of the aggregation set needs to be
different.

Information noteWarning:

The columns in the Key table must NOT appear in the Operations table. If you
want all the columns of the output schema to be filled in, they must appear either
in the Key table or in the Operations table. | | Operations | Output column: From the list, select the output
column which will result from the selected merge operation.

Function: Select the type of merge operation to be
performed from the list. The list includes count,
min, max,
avg, sum,
first, last,
list, list(object), count(distinct),
standard deviation, max
length and best rank.

Input column: From the list, select the input
column from which the values are to be selected for the merge operation.

Rank column: Only available with the best rank function. From the list, select the column you
want to use as a rank value for the merge operation. Then the input column will be
replaced with the value which has the greater rank.

Ignore null values: Select the check boxes which
correspond to the names of the columns for which you want the NULL value to be
ignored. | ## Advanced settings | Properties | Description | | --- | --- | | Delimiter (only for list operation) | Between double quotation marks, enter the delimiter you want to use for the list
operation. | | Use financial precision, this is the max precision for "sum" and "avg"
operations, checked option heaps more memory and slower than
unchecked. | This check box, which enables financial precision, is selected by default. Clear
the check box if you want to use less memory and thus optimize performance. | | Check type overflow (slower) | Checks the data type to ensure that the Job does not crash.

If you select this check box, the system will be slower. | | Check ULP (Unit in the Last Place), ensure that a value will be
incremented or decremented correctly, only for float and double types.
(slower) | Select this check box to launch ULP verification.

If you select this check box, the system will be slower. | | tStatCatcher Statistics | Select this check box to collect log data at the Job and the component
levels. | ## Global Variables | Variables | Description | | --- | --- | | 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 more information about variables, see [Using contexts and variables](https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/contexts-and-variables). | ## Usage | Usage guidance | Description | | --- | --- | | **Usage rule** | This component requires an input component and an output component. |