To access a dataset generated by an external application on a Terracotta server, you must first configure a Terracotta connection in MashZone NextGen. You can define Terracotta connections in the MashZone NextGen Admin console. For details, see Manage Terracotta connections.
Select a Terracotta connection in the Terracotta alias drop-down menu. The alias specifies the Terracotta server with which you want to connect. The menu contains all available Terracotta connections for which you have Usage privilege.
Select a dataset alias in the Dataset name drop-down menu. The menu contains all available Terracotta datasets for the selected Terracotta alias. For details, see Manage Terracotta connections. Datasets generated by MashZone NextGen for Materialized Feeds on the Terracotta server are excluded from the list.
Click Configure columns to configure the columns of the dataset.
When you select a dataset, schema guessing is used to derive its columns. Using 1000 records, the guessing mechanism derives the set of all unique cell definitions of those records and defines corresponding columns.
Disable a column to exclude it from processing.
Select or enter a (positive) Sample size and click Derive columns to re-run the schema guessing with a larger sample size. The current configuration is omitted. The larger the sample size is, the longer the schema guessing takes.
Click Add column to manually add a new column.
Enter a unique column name and select a data type for the new column.
The combination of name and type must match the cell definition in the store. If does not fit the definition, the corresponding values are always null. For example, if the cell definition is age with type INT and you specify age with type DOUBLE, the column definition does not correspond to the cell definition and the values are null.
Configure the RAQL query, refresh rate, and input parameters. For details, see Terracotta data source.