Configuring Change Processing settings

Perform the following steps to configure change processing settings.

To configure change processing settings:

1. Select the Change Processing tab in the Teradata Database source.

2. In the Columns field, specify the names of the Context columns. The column names are case-sensitive and must be separated by commas.

   Example:  

   context1,context2

3. Choose the sorting order of the Context columns as appropriate (Ascending or Descending). Note that if the order you select is not the same as the actual sorting order, an error will occur.
4. In the Check for changes every field, specify how often to check for changes.

5. Enter expressions that Replicate will use to identify UPDATE and DELETE operations. If you do not enter any expressions or if no match is found for an expression, any row whose context is higher (if the sorting order is Ascending) or lower (if the sorting order is Descending) than the previous context value will be considered an INSERT.

   Information note

   Expressions must be written in the native syntax of the Teradata Database source. All examples in this section are written using PostgreSQL syntax.

   • Update expression - Enter an expression for identifying UPDATE operations.

     Example (based on Figure "Example of a Table with a Context Column"):

     case when oper='U' then 1 else 0 end

     Information note

     [Selecting the UPDATE the existing target record option in the Apply Conflicts tab, eliminates the need to provide an UPDATE expression.

   • Delete expression - Enter an expression for identifying DELETE operations.

     Example (based on Figure "Example of a Table with a Context Column"):

     case when oper='D' then 1 else 0 end

     Information note

     In addition to the DELETE expression, DELETE operations should be carried out as "Soft" deletes. This means that the row is not actually deleted from the table, but rather, marked as "deleted".

6. Select Override connection string parameters to append the connection string with parameters that are not exposed in the UI. As such parameters are normally not required, they should only be used after consulting with Qlik Support.