Adding Row Level Security to a Pentaho Metadata Model
Row Level Security allows you to control the results that are returned in a query based on a user's security level. You can specify which rows of data each User Role or User ID is allowed to retrieve from the database, based on some column of data, or combination of columns of data.
Within the Metadata Editor, select the model to add Row Level Security to, right click on the Model, and select "Edit...".
WARNING: Row Level Security is only in effect at the Model level. Any data constraints defined below the Model Level, such in a Business Table or Business Column, is ignored and not used.
From the Model Properties dialog, select the General -> Data Constraints Property:
By default, Row Level Security is not enabled. There are two forms of Row Level Security in Pentaho Metadata, Global Constraint and Role Based Constraints.
If using the Global Constraint, a single MQL Formula is used to define security for all users. In addition to the standard MQL Functions available, there are also two additional functions available.
- USER() - returns the name of the current user
- ROLES() - returns a list of roles the current user has.
Example of Global Constraints
This example defines an MQL Formula that allows Admins full access, and everyone else no access
Role Based Constraints
If using Role Based Constraints, the Metadata engine determines which MQL constraints apply to the current user and apply them to the current query. Constraints may be added for each Role and User within a system. If zero constraints match a user and their roles, no data is returned by the MQL query. If more than one constraint applies to a user, then the constraints are OR'ed together to determine row visibility.
Example of Role Based Constraints
This example defines an MQL Formula for three different roles. The Admin Role has full row visibility, the Sales and Engineering Roles may only see data that joins to rows with their particular department. (The syntax is [business_table.business_column] = value).
Row Level Security Constraints are applied at the MQL Layer. The Business Columns referenced in the MQL Security Constraints will be resolved down to SQL Table Columns. The Tables which contain column references included in security constraints will be joined to your query, based on the relationships defined in the Business Model. It is recommended that you do not use outer joined business columns for the purposes of security constraints.