We have AUTOTRAN = Y in our UBB and we are not sure if we need it.

Question

Hi All
And thanks in advance.
We have several questions in regard to the AUTOTRAN parameter.
We have AUTOTRAN = Y in our UBB and we are not sure if we need it.
1.) Would "AUTOTRAN = Y" start a transaction for SELECT only queries?
2.) How does "AUTOTRAN = Y" affect CORBA calls where we do call BEGIN, COMMIT and ABORT explicitly?
2a.) How does "AUTOTRAN = Y" affect RAC failover scenario in this case?
4.) How does "AUTOTRAN = Y" affect /Q services calls (GTT)?
* For example (TMQFORWORD -> SERVICE (TMS_ORACLE) )
* The relevant services DO NOT call BEGIN, COMMIT or ABORT explicitly rather relay on TMQFORWORD for that.
Many Thanks
Tech Sgin

Answer 1

Hi,
Services marked with AUTOTRAN=Y indicate that Tuxedo should automatically start a transaction if one has not already been started. If Tuxedo started a transaction as a result of AUTOTRAN=Y, Tuxedo will commit the transaction when the service completes.
In answer to your specific questions:
1.) Would "AUTOTRAN = Y" start a transaction for SELECT only queries?Tuxedo doesn't know what a SELECT statement is. As mentioned above, if a transaction has not been started when a service marked AUTOTRAN=Y is called, Tuxedo will effectively perform a tpbegin() on the behalf of the caller.
2.) How does "AUTOTRAN = Y" affect CORBA calls where we do call BEGIN, COMMIT and ABORT explicitly?CORBA calls are no different than ATMI calls with respect to AUTOTRAN. Interfaces market with AUTOTRAN=Y will have transactions started if one has not already been started prior to an operation on the interface being called. Note, the transaction policy in the ICF file must be set to OPTIONAL for AUTOTRAN on an interface to do anything. Otherwise the transaction policy as defined by the ICF file is followed.
2a.) How does "AUTOTRAN = Y" affect RAC failover scenario in this case?What do you mean by "RAC failover scenario"? Again, simply think of AUTOTRAN=Y as being the exact same behavior as if the caller did:
if (!tpgetlev())
    tpbegin();
tpcall(...);
if (!tpgetlev())
    tpcommit();
4.) How does "AUTOTRAN = Y" affect /Q services calls (GTT)?
* For example (TMQFORWORD -> SERVICE (TMS_ORACLE) )
* The relevant services DO NOT call BEGIN, COMMIT or ABORT explicitly rather relay on TMQFORWORD for that.GTT? Global Transaction Table? I'm not following. With regards to TMQFORWARD, although you can use AUTOTRAN=Y and then tell TMQFORWARD to not make the call in the context of a transaction, the risk you run there is that the dequeuing of the message from the request queue will also not be done in a transaction. Thus in some failure scenarios a request could be lost. It is better to let TMQFORWARD begin the transaction so it can include the dequeuing of the request, the actual service call, AND the enqueuing of the reply all in a single transaction.
I hope I answered your questions.
Regards,
Todd Little
Oracle Tuxedo Chief Architect