Migrating Precompiler or OCI Applications to TPM Applications

1. Reorganize the application into a framework of "services."

This means that application clients request services from application servers.

Some TPMs require the application to use the tx_open and tx_close functions, whereas other TPMs do the logon and logoff implicitly.

If you do not specify the sqlnet parameter in your open string, the application will use the default SQL*Net driver. Thus, you need to be sure that the application server is brought up with the ORACLE_HOME and ORACLE_SID environment variables properly defined. This is accomplished in a TPM-specific fashion. See your TPM vendor documentation for instructions on how to accomplish this.

2. Ensure that the application replaces the regular connect and disconnect statements.

For example, replace the connect statements EXEC SQL CONNECT (for precompilers) or olon() (for OCIs) by tx_open(). Replace the disconnect statements EXEC SQL COMMIT/ROLLBACK RELEASE WORK (for precompilers), or ologof() (for OCIs) by tx_close().

3. Ensure that the application replaces the regular commit/rollback statements and begins the transaction explicitly.

For example, replace the commit/rollback statements EXEC SQL COMMIT/ROLLBACK WORK (for precompilers), or ocom()/orol() (for OCIs) by tx_commit()/tx_rollback() and start the transaction by calling tx_begin().

4. Be sure to use release_cursor=yes, and to close all explicit cursors before committing a transaction.

Regular Oracle Commands	TPM Functions
CONNECT user/password	tx_open (possibly implicit)
implicit start of transaction	tx_begin
SQL	service that executes the SQL
COMMIT	tx_commit
ROLLBACK	tx_rollback
disconnect	tx_close (possibly implicit)
SAVEPOINT savepoint	illegal
SET TRANSACTION READ ONLY	illegal

Table 7 - 1. TPM Replacement Commands