Terracotta DB

Extracts data from datasets managed by a Terracotta DB server and runs RAQL queries over the data. The available datasets were either generated by an external application or by MashZone NextGen for materializing data feed results. You must select one of those two categories of datasets. Depending on your selection, the source operator shows different parameters.

To use the Terracotta DB source operator, you must configure a Terracotta DB connection in MashZone NextGen in advance. Terracotta DB connections can be defined in the MashZone NextGen Admin console. See Manage Terracotta DB connections.

The following parameters are available for the Datasets and Materialized Feeds source types.

Parameters

Description

Source

Specifies the data source type.

  • Datasets
  • Materialized Feeds

Select a source type.

Terracotta DB alias

List of available Terracotta DB datasets for the configured connection aliases.

Only Dataset aliases for that you have the Usage privilege are available. Select a Dataset alias. See Manage Terracotta DB connections for details.

The option is available if the Datasets source type is selected.

Materialized Feed

List of available Materialized Feed aliases.

Only Materialized Feed aliases for that you have the Usage privilege are available. Select the alias which defines the dataset with the Materialized Feed results. The corresponding dataset is available in the Dataset name drop-down menu. See Manage Materialized Feeds for details.

The option is available if the Materialized Feeds source type is selected.

Dataset name

List of available Terracotta DB datasets for the configured connection alias. Select a

dataset

.

The option is available if the Datasets source type is selected.

Refresh rate ()

Specifies the time until the data source is read in again. Default value is 12 h.

RAQL query

Input field to enter any RAQL statement.

Preset query: SELECT * FROM Dataset

Dataset is the selected entry from the Dataset Alias drop-down box.

Insert parameter (Insert parameter)

Inserts user defined input parameters at the cursor position. The button is clickable only if at least one user input parameter, for example, Text user input, has been inserted in the feed definition.

For details, see RAQL and SQL statement parameters.

Expand (Expand)/

Collapse (Collaps)

Expands or collapses the query input box.

Configure columns

Configures the columns of the dataset.

The option is available if the Datasets source type is selected.

When selecting 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. Use Configure columns to display or modify that schema.

Unselect 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, thereby omitting the current configuration. Note that 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. Note that the combination of name and type has to fit to the cell definition in the store. If not, the corresponding values will always be null. For example, if the cell definition is age with type INT and you specify age with type DOUBLE, the column definition does not fit to the cell definition and the values are null.