Map Relational Schemas to MongoDB
Business intelligence tools connect to a data source and, given a fixed tabular schema, allow users to visually explore their data. MongoDB uses a flexible schema, so some business intelligence tools cannot use MongoDB as a native data source.
To use MongoDB with a relational business intelligence tool such as Tableau, you must define a relational mapping for your MongoDB data. MongoDB Connector for BI provides several methods for creating and managing a relational schema.
For complete documentation on BI Connector's schema management options,
see the mongosqld reference documentation.
Standalone Schema Mode (Cached Sampling)
The default sampling mode which mongosqld uses to
analyze your collections and derive a static schema. In this mode,
mongosqld derives the schema on startup and holds the
schema in memory.
Auto Schema Mode (Persist a Schema in MongoDB)
mongosqld samples your MongoDB collections and
creates a schema at the time of startup and writes it to a
MongoDB collection. Available via the --schemaSource option.
Use MongoDB Views
MongoDB views allow you to control the display of information from a collection by restricting access to certain fields, renaming fields, sorting data, and other techniques. BI Connector can read data from a view just as it does from a standard collection.
Load a Schema from a DRDL File
You can generate a text schema for mongosqld to use
with the mongodrdl program. You can edit a text
schema manually to suit your particular data needs.
Resample Schema Data with "FLUSH SAMPLE"
If the data in your MongoDB instance changes shape significantly
with new fields or collections, you may wish to regenerate the
schema BI Connector uses. You can regenerate the schema either by
restarting mongosqld or by issuing the "FLUSH
SAMPLE" command from within the MySQL shell.
Geospatial Data
BI Connector handles collections which contain a 2d or 2dsphere
geospatial index such
that longitude and latitude data are represented within a single
table along with other collection data.
Sampling Type Conflicts
Relational databases don't allow dynamically typed columns. When the BI Connector samples data from MongoDB to generate a schema, type conversion conflicts may occur. To learn more about how the BI Connector resolves these conflicts and displays data when conflicts are present, see the following sections.