Chapter 9: Using Bulk Copy Transfer and Express Transfer

Overview

Bulk copy and express transfer initiate a direct transfer of data between two databases from the client application. You use a bulk copy or express transfer statement to copy large amounts of data between similar tables. The following table describes the conditions that determine which type of transfer you select.

**Table 9-1: When to use bulk copy and express transfer**
Use bulk copy transfer:	Use express transfer:
When the source or destination database is ASE and does not use an ASE ODBC driver.	When you use ODBC drivers for both the source and destination database.
To exercise more control over transfer.	To execute the transfer quickly.
When you require diverse datatype conversions.	When you do not require any datatype conversions.

Limitations for bulk copy and express transfer

For bulk copy and express transfer, the following limitations apply:

The transfer statement must be the only statement in a request.
The table (the target) into which you want to transfer data must already exist, because the transfer statement does not create new tables.
The structure of the target table must match the structure of the source table.
For bulk copy and express transfer to work, the secondaryname to the secondary database must be recorded in the following DirectConnect files:
- For bulk copy transfer, the interfaces file for UNIX, or in the sql.ini file for Windows.
- For express transfer, the secondaryname must match a Data Source Name (DSN) in the ODBC system information file.
Unicode datatypes are not supported.
The first 32K of long character and long binary values are supported. Transfer processing truncates longer values without any warning.

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