MSDN documenation for DbConnection.GetDBSchema says -
Returns schema information for the data source of this DbConnection using the specified string for the schema name and the specified string array for the restriction values.
Regarding the restriction values
The restrictionValues parameter can supply n depth of values, which are specified by the restrictions collection for a specific collection. In order to set values on a given restriction, and not set the values of other restrictions, you need to set the preceding restrictions to null and then put the appropriate value in for the restriction that you would like to specify a value for.
An example of this is the "Tables" collection. If the "Tables" collection has three restrictions (database, owner, and table name) and you want to get back only the tables associated with the owner "Carl", you must pass in the following values at least: null, "Carl".
How do I obtain tables associated with multiple users or in case of the 'Columns' collection how can I specify 2 tables in order to get columns for only these 2 tables or do I have to call the method twice specifying each table individually?