# tPostgresPlusSCDELT Addresses Slowly Changing Dimension needs through SQL queries (server-side processing mode), and logs the changes into a dedicated PostgresPlus SCD table. The tPostgresPlusSCDELT reflects and tracks changes in a dedicated Oracle SCD table. ## tPostgresPlusSCDELT Standard properties These properties are used to configure tPostgresPlusSCDELT running in the Standard Job framework. The Standard tPostgresPlusSCDELT component belongs to the Business Intelligence and the Databases families. The component in this framework is available in all Talend products. Information noteNote: This component is a specific version of a dynamic database connector. The properties related to database settings vary depending on your database type selection. For more information about dynamic database connectors, see [DB Generic components](https://help.qlik.com/talend/r/en-US/8.0/components/db-generic/db-generic-component). ## Basic settings | Properties | Description | | --- | --- | | Database | Select the desired database type from the list and click
Apply. | | Property type |

Either Built-in or Repository.
Built-in: No property data stored centrally. Enter properties manually.
Repository: Select the repository file where Properties are stored. The fields that come after are pre-filled in using the fetched data.

| | Use an existing connection | Select this check box and in the Component
List drop-down list, select the desired connection component to
reuse the connection details you already defined.

Information noteNote: When a Job contains the parent Job and the child Job, do the following if you
want to share an existing connection between the parent Job and the child Job (for example,
to share the connection created by the parent Job with the child Job).

In the parent level, register the database connection to be shared in the Basic settings view of the connection component which creates that very database connection.
In the child level, use a dedicated connection component to read that registered database connection.

For an example about how to share a database connection across Job levels,
see [Sharing a database connection](https://help.qlik.com/talend/r/en-US/7.3/studio-user-guide/sharing-database-connection). | | DB Version | List of database versions. | | Host | The IP address of the database server. | | Port | Listening port number of database server. | | Database | Name of the database. | | Schema | Exact name of the schema | | Username and
Password | User authentication data for a dedicated database.

To enter the password, click the [...] button
next to the password field, enter the password in double quotes in the pop-up dialog box,
and click OK to save the settings. | | Source table | Name of the input DB2 SCD table. | | Table | Name of the table to be written. Note that only one table can be
written at a time | | Action on table | Select to perform one of the following operations on the table
defined:

None: No action carried out on the
table.

Drop and create table: The table is
removed and created again

Create table: A new table gets
created.

Create table if not exists: A table
gets created if it does not exist.

Clear table: The table content is
deleted. You have the possibility to rollback the operation.

Truncate table: The table content
is deleted. You don not have the possibility to rollback the
operation. | | 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 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: The schema is 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. For more information about a component schema in its Basic settings tab, see Basic settings tab.

| | Surrogate Key | Select the surrogate key column from the list. | | Creation | Select the method to be used for the surrogate key
generation.

For more information regarding the creation methods, see [SCD management methodology](https://help.qlik.com/talend/en-US/components/8.0/scd/scd-management-methodology). | | Source Keys | Select one or more columns to be used as keys, to ensure the
unicity of incoming data. | | Use SCD Type 1 fields | Use type 1 if tracking changes is not necessary. SCD Type 1 should
be used for typos corrections for example. Select the columns of the
schema that will be checked for changes. | | Use SCD Type 2 fields | Use type 2 if changes need to be tracked down. SCD Type 2 should
be used to trace updates for example. Select the columns of the
schema that will be checked for changes. | | SCD type 2 fields | Click the [+] button to add as many rows as needed, each row for a column. Click
the arrow on the right side of the cell and select the column whose value changes will
be tracked using Type 2 SCD from the drop-down list displayed .

This table is available only when the Use SCD type 2 fields
option is selected. | | Start date | Specify the column that holds the start date for
type 2 SCD.

This list is available only when the Use SCD type 2 fields
option is selected. | | End date | Specify the column that holds the end date for type
2 SCD.

This list is available only when the Use SCD type 2 fields
option is selected.

Information noteNote: To avoid duplicated change records, it is recommended to
select a column that can identify each change for this field. | | Log active status | Select this check box and from the
Active field drop-down list displayed, select
the column that holds the true or false status value, which helps to spot the active
record for type 2 SCD.

This option is available only when the Use SCD type 2 fields
option is selected. | | Log versions | Select this check box and from the Version field drop-down list displayed, select the column
that holds the version number of the record for type 2 SCD.

This option is available only when the Use SCD type 2 fields
option is selected. | ## Advanced settings | Properties | Description | | --- | --- | | Additional JDBC Parameters | Specify additional JDBC parameters for the database connection created.

This property is not available when the Use an existing connection check box in the Basic
settings view is selected. | | Debug mode | Select this check box to display each step during processing
entries in a database. | | tStatCatcher Statistics | Select this check box to collect log data at the component
level. | ## 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 checkbox is
cleared, if the component has this checkbox.

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 is used as an output component. It requires an
input component and Row main link as input. | | Dynamic settings | Click the [+] button to add a row in the table
and fill the Code field with a context
variable to choose your database connection dynamically from multiple
connections planned in your Job. This feature is useful when you need to
access database tables having the same data structure but in different
databases, especially when you are working in an environment where you
cannot change your Job settings, for example, when your Job has to be
deployed and executed independent of Talend Studio.

The Dynamic settings table is
available only when the Use an existing
connection check box is selected in the Basic settings view. Once a dynamic parameter is
defined, the Component List box in the
Basic settings view becomes unusable.

For examples on using dynamic parameters, see [Reading data from databases through
context-based dynamic connections](https://help.qlik.com/talend/r/en-US/8.0/components/defining-context-groups/reading-data-from-databases-through-context-based-dynamic-connections) and [Reading data from different MySQL databases
using dynamically loaded connection parameters](https://help.qlik.com/talend/r/en-US/8.0/components/context/reading-data-from-different-mysql-databases-using-dynamically-loaded-connection-parameters). For more information on
Dynamic settings and context variables, see
[Dynamic schema](https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/dynamic-schema) and [Creating a context group and define context
variables in it](https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/creating-context-group-and-define-context-variables-in-it). |