Transactional behavior is puzzling

[JeffTSG]

In one package, I have tried to isolate d/b activity of a component (#B) by setting it to "requires new tx". It is invoked by a master component (#A) that is set to "requires tx." I get Distributed TX errors and I'm hoping someone can tell me why!?

If I change #B to 'no tx' support, it can add a new record, but times out when updating a record. This is also is puzzling.

MTS is on one machine and SQL 6.5 on another.

Thanks,

 

[BML]

Hi Jeff,

you can find MTS SPY here

http://msdn.microsoft.com/training/free/chapters/mvs/mvs01018.htm

When you use #A the registers in DB became locked. When you invoke #B and try to use the same registers, you receive an error, because #A haven't done commit on those registers.

I think that's the reason that you can make insert's but not updates.

The settings are correct, I have components working with those settings.

regards,

Bruno Loureiro
<brunoloureiro@usa.net>

 

[Guest_imported]

I think B should be set to 'Supports transactions' or Requires New' since it is the 'child' and A to 'Requires New' or 'Requires a transaction' since it is the 'Parent'.

EjL

 

[BML]

Hi Mr. E,

if you set #B to 'Supports Transactions', it will be running in the same transaction as #A, so the commit will only be done when #A commits.

If #B is set to 'Requires New Transaction' and #A to 'Requires New Transaction' or 'Requires Transaction', then if #A does an Insert into the table tbSample and #B tries to update that same record, it will raise an error, because #A hasn't commited (the record is locked). The same thing will happen if #A does an Insert into tbSample.id and #B tries to insert into tbSample2.id, that is FK of tbSample.id, because the record in tbSample is locked (#A hasn't commited).

regards,

Bruno Loureiro
<brunoloureiro@usa.net>

 

[TomSark]

BML is correct. If you run B in the same transaction as A
this should work.

If not, do the above, and, set your isolation level to READ COMMITTED, then you should be able to do this...
Tom Davis
tdavis@sark.com

http://www.sarkdallas.com

 

[TomSark]

Please read the FAQ I have posted in this forum (faq330-397). Also, there is a great book that you can read to learn more about this by Ted Pattision, entitled &quot;Programming Distributed Applications with COM and Microsoft Visual Basic 6.0&quot;.

Chapters 9 and 10 of this book should provide you with the details needed to clear up this fuzzy issue... (no pun on policitics intended). Tom Davis
tdavis@sark.com

http://www.sarkdallas.com