Materialized Views API (Experimental)

This applies to: Visual Data Discovery

The Materialized Views API is deprecated. This API will be removed in a future release.

Materialized view functionality is disabled by default. To enable, contact technical support for assistance.

Materialized views allow you to use pre-aggregated query results, stored in some external storage, to speed up query processing in certain scenarios, especially when processing a query with heavily aggregated data.

Pre-aggregated data is not managed by Symphony, so it should be maintained manually and kept up to date by the owner of the data.

This is an experimental feature.

The Volume metric is required in all materialized view definitions.

API support for materialized views is performed using the REST API endpoint /api/materialized-views, as described below.

Endpoint	Method	Description
/api/materialized-views	GET	Returns a list of all materialized view mappings. Optionally, include the sourceId={<data-source-id>} parameter to obtain a list of materialized views for a specific data source.
/api/materialized-views	POST	Creates a new materialized view mapping.
/api/materialized-views/<source-ID>	PUT	Updates a specific materialized view mapping.
/api/materialized-views/<source-ID>	PATCH	Patches (partially updates) a specific materialized view mapping.
/api/materialized-views/<source-ID>	DELETE	Deletes a specific materialized view mapping.
/api/sources/<source-ID>/fields/meta	GET	Returns information about all the fields and metrics in a data source.

API documentation is provided with your Symphony installation at this link: <symphony-URL>/discovery/swagger-ui.html.

Here is a sample of the general object structure for materialized views:

{
  "name": "string",
  "description": "string",
  "enabled": true,
  "definition": { ... },
  "storageSettings": {
    "targetStorage": { ... },
    "fieldMappings": [ ... ]
  }
}

Each object is described in the following table.

Object	Specifies
name	The name of the materialized view definition.
description	The description of the materialized view definition.
enabled	Whether or not the definition is enabled. A value of true indicates that it is enabled; false indicates that it is not.
definition	The query that this materialized view should match.
storageSettings	Where the data for the query results are stored.
targetStorage	The connection and the specific table or collection of data
fieldMappings	The mapping between the fields used in the definition and the columns or fields in the data identified by the targetStorage object. Every field returned by the definition query should be mapped in fieldMappings. You can skip fields in the target table if they are not used in the query results (for example, redundant metrics).