Please help me to understand Transaction option in SSIS container

Question

Hi experts,
 I am confused about Transaction option in SSIS container,
1. Required - Start the transaction. What is mean that start transaction?
2.Supported- join the transaction ..
can you please help me to understand.
Thanks

Answer 1

I think Vaibhav already answered your question but here's more from my end.
1. 
    Package - Transaction Option - Supported
    SEQC - Transaction Option - Supported
    3 Execute SQL Tasks - Transaction Option - Supported
So, package / SEQC / SQL 1 / SQL 2 / SQL 3 doesn't involve in a transaction i.e. think of those tasks are not included in
BEGIN TRANSACTION / COMMIT TRANSACTION
Sequence Container
--Execute SQL Task 1
INSERT INTO dbo.t1 (a)   
SELECT 10
--Execute SQL Task 2
INSERT INTO dbo.t1 (a) 
SELECT 11
--Execute SQL Task 3
INSERT INTO dbo.t1 (a) 
SELECT 'aa'
When we execute package, it will insert 10, 11 values into table dbo.t1 and since there's an error in the 3rd statement, it'll fail
2.  
    Package - Transaction Option - Required
    SEQC - Transaction Option - Supported
    3 Execute SQL Tasks - Transaction Option - Supported
Now, package will Start a transaction since it's Transaction Option is "Required" , so now the SEQC (3 Execute SQL tasks) will
be inside transaction / join the transaction because their transaction option is "Supported".
Package - Information: Starting distributed transaction for this container. --BEGIN TRANSACTION 
(You'll see this statement in Processing / Execution Results tab)
SEQC
--Execute SQL Task 1
INSERT INTO dbo.t1 (a)   
SELECT 21
--Execute SQL Task 2
INSERT INTO dbo.t1 (a) 
SELECT 22
--Execute SQL Task 3
INSERT INTO dbo.t1 (a) 
SELECT 23
Package - Information: Committing distributed transaction started by this container. -- COMMIT TRANSACTION 
(You'll see this statement in Processing / Execution Results tab)
When we execute package, it will insert 21, 22, 23 values into table dbo.t1 and also you can see the START TRANSACTION /
COMMIT TRANSACTION in the Exection Results tab are at the Package Level and not at the Sequence Container level.
Without any change, if you change the value from 23 to 'aa' in the 3rd Execute SQL task then you'll see 
Information: Aborting the current distributed transaction. statement in the 3rd Executed SQL Task in Execute Results tab
which is at the Sequence container / Execute SQL task 3 level and it's because their Transaction option is Supported and so they
joined the transaction 
Please see the screenshot below that under Package, the START TRANSACTION but ABORT TRANSACTION is at Execute SQL task
level
3. 
    Package - Transaction Option - Supported
    SEQC - Transaction Option - Required
    3 Execute SQL Tasks - Transaction Option - Supported
Please see the screenshot below that under Sequence Container, the TRANSACTION has started. Since the the Sequence container's
parent (which is package) has not started any transaction and so the it started it's own transaction. 
4. 
    Package - Transaction Option - Required
    SEQC - Transaction Option - Required
    3 Execute SQL Tasks - Transaction Option - Supported
See the screenshot below which is same as first screenshot.
Since Package's transaction property is set to "Required" and it's Parent to Sequence Container 
and so package started the started the transaction, and  though Sequence container's transaction option is "Required", 
it will not start a new transaction rather it "joins" the transaction that was already opened by it's Parent (Package). 
Now, if we see the definitions what Supported and Required means - 
Supported - Specifies that this container will not start a transaction. 
However, it will participate in a transaction if the parent container started one. This is the default. (4th Example)
Required - Specifies that this container will cause a new transaction to be started unless the parent container already has a transaction, 
 in which case, the parent’s transaction will be joined. (2nd and 3rd Examples)
Narsimha