SchemaPreload

The SchemaPreload function initializes the attribute and class tables for import and export operations. Microsoft Exchange Server executes the SchemaPreload function in the background as a separate thread.

Quick Info

VOID SchemaPreload(
  DWORD dwFlags, 
  LPTSTR pszDSA  
);
 

Parameters

dwFlag

Accepts defined values that control the directory schema operations. Use the bitwise OR operator (|) to enable multiple operations:

DAPI_FORCE_SCHEMA_LOAD

Unloads a previously loaded schema and reads the schema again. The default action is to reuse the previously loaded schema if read from the same messaging domain.

DAPI_RAW_MODE

Imports and exports in raw mode, where import lines are taken literally. Attributes are neither inherited nor constructed, and aliases for attribute and class names are not recognized.

Flags That Control Event Filtering:

DAPI_EVENT_MIN

Logs start and stop messages. Provides no warning or error logging.

DAPI_EVENT_SOME

Logs Start, Stop, and Error messages.

DAPI_EVENT_ALL

Logs Start, Stop, Error, and Warning messages.

pszDSA

The name of the directory service agent where the schema is read.

Return Values

None.

Remarks

The SchemaPreload function is optional. It allows an image of the directory schema to be loaded by a separate Windows NT Server thread while the directory access process is being initialized. For example, your program can load the schema while a user is entering import or export parameters in a dialog.

Microsoft Exchange Server uses the schema that was loaded into the schema cache for all subsequent directory access operations, until one of the following events occurs:

• DAPI.DLL is unloaded from memory.
• SchemaPreload is called with the DAPI_FORCE_SCHEMA_LOAD flag, which flushes current schema values in the cache and reloads a new copy of the schema.
• A directory access or export operation is specified with a different messaging site.

For more information on this function, see Using Directory Access Functions.

See Also

BatchExport, BatchImport, DAPIRead, DAPIWrite