.NET Data Provider for Teradata supports Schema discovery. TdConnection.GetSchema methods return information about Common Schema Collections or Provider-Specific Schema Collections.
All .NET Data Providers implement five Common Schema Collections. The exact layout is dictated by the ADO.NET 2.0 specification.
| Common Schema Collection | Description |
|---|---|
| MetaDataCollections | Returns information about all supported schema collections. This is basically a list of Common and Provider-Specific schema collections. |
| DataSourceInformation | Returns information about the Advanced SQL Engine. For example it returns the SQL Engine version for the current connection. |
| DataTypes | Returns information about the Data Types supported by SQL Engine associated with the current connection. For example Teradata Database 6.2 supports Big Integer while Teradata Database 6.1 does not support Big Integer Data Type. |
| Restrictions | Returns information about restriction or filters available for each supported schema collection. |
| ReservedWords | Returns the list of reserved words for the SQL Engine version associated with current connection. |
.NET Data Provider for Teradata Provider-Specific collections are dependent on the SQL Engine Data Dictionary System Views like DBC.TABLES or DBC.TABLESX. User must have access rights to Non-X and or X System Views. .NET Data Provider for Teradata will generate SELECT statements against X System Views when UseXViews Connection setting is set to true. UseXViews is set to true by default. Provider will access Unicode Data Dictionary System Views (e.g. DBC.TABLESV) when connected to Teradata Database version 12.0 or higher.
Each one of the Provider-Specific schema collections supports restrictions to filter the result set. These restrictions (object names) must be compatible in the current session character set. If they are not compatible, the SQL Engine will translate/convert these object names and replace the untranslatable characters with a translation error character. A Unicode session character set is recommended to eliminate the translation errors. For more information see Using Extended Object Names in Schema Collections and Visual Studio.
| Provider Specific Collection | Description |
|---|---|
| Columns | Returns information about COLUMN objects including data type and length. |
| ForeignKeys | Returns information about FOREIGN KEY constraint relationship between two tables. |
| Indexes | Returns information about INDEX objects including Columns whose values are indexed. |
| MacroParameters | Returns information about Input Parameters for Macros. |
| Macros | Returns information about MACRO objects. |
| PrimaryKeys | Returns information about PRIMARY KEY constraint. |
| ProcedureParameters | Returns information about Input, Input-Output and Output Parameters for SQL and External Stored Procedures. |
| Procedures | Returns information about PROCEDURE objects including EXTERNAL Stored Procedures. |
| Schemata | Returns information about DATABASE objects. |
| Statistics | Returns statistics for TABLE, JOIN INDEX and HASH INDEX objects. |
| Tables | Returns information about TABLE and VIEW objects. |
| UserDefinedFunctionParameters | Returns information about Input Parameters for User Defined Functions. |
| UserDefinedFunctions | Returns information about USER DEFINED FUNCTION objects including Scalar, Table and Aggregate User Defined Functions. |
| UserDefinedTypes | Returns information about USER DEFINED TYPE objects. |